diff --git a/core/bootstrap.js b/core/bootstrap.js
index 8e0737f06d..c632e0c776 100644
--- a/core/bootstrap.js
+++ b/core/bootstrap.js
@@ -6,7 +6,7 @@
 
 var fs      = require('fs'),
     url     = require('url'),
-    when    = require('when'),
+    Promise = require('bluebird'),
     validator = require('validator'),
     errors  = require('./server/errors'),
     config  = require('./server/config'),
@@ -20,43 +20,42 @@ function readConfigFile(envVal) {
 }
 
 function writeConfigFile() {
-    var written = when.defer();
-
     /* Check for config file and copy from config.example.js
         if one doesn't exist. After that, start the server. */
-    fs.exists(configExample, function checkTemplate(templateExists) {
-        var read,
-            write,
-            error;
+    return new Promise(function (resolve, reject) {
+        fs.exists(configExample, function checkTemplate(templateExists) {
+            var read,
+                write,
+                error;
 
-        if (!templateExists) {
-            error = new Error('Could not locate a configuration file.');
-            error.context = appRoot;
-            error.help = 'Please check your deployment for config.js or config.example.js.';
+            if (!templateExists) {
+                error = new Error('Could not locate a configuration file.');
+                error.context = appRoot;
+                error.help = 'Please check your deployment for config.js or config.example.js.';
 
-            return written.reject(error);
-        }
+                return reject(error);
+            }
 
-        // Copy config.example.js => config.js
-        read = fs.createReadStream(configExample);
-        read.on('error', function (err) {
-            errors.logError(new Error('Could not open config.example.js for read.'), appRoot, 'Please check your deployment for config.js or config.example.js.');
+            // Copy config.example.js => config.js
+            read = fs.createReadStream(configExample);
+            read.on('error', function (err) {
+                errors.logError(new Error('Could not open config.example.js for read.'), appRoot, 'Please check your deployment for config.js or config.example.js.');
 
-            return written.reject(err);
+                reject(err);
+            });
+
+            write = fs.createWriteStream(configFile);
+            write.on('error', function (err) {
+                errors.logError(new Error('Could not open config.js for write.'), appRoot, 'Please check your deployment for config.js or config.example.js.');
+
+                reject(err);
+            });
+
+            write.on('finish', resolve);
+
+            read.pipe(write);
         });
-
-        write = fs.createWriteStream(configFile);
-        write.on('error', function (err) {
-            errors.logError(new Error('Could not open config.js for write.'), appRoot, 'Please check your deployment for config.js or config.example.js.');
-
-            return written.reject(err);
-        });
-        write.on('finish', written.resolve);
-
-        read.pipe(write);
     });
-
-    return written.promise;
 }
 
 function validateConfigEnvironment() {
@@ -70,7 +69,7 @@ function validateConfigEnvironment() {
         config = readConfigFile(envVal);
     }
     catch (e) {
-        return when.reject(e);
+        return Promise.reject(e);
     }
 
     // Check if we don't even have a config
@@ -78,14 +77,14 @@ function validateConfigEnvironment() {
         errors.logError(new Error('Cannot find the configuration for the current NODE_ENV'), 'NODE_ENV=' + envVal,
             'Ensure your config.js has a section for the current NODE_ENV value and is formatted properly.');
 
-        return when.reject(new Error('Unable to load config for NODE_ENV=' + envVal));
+        return Promise.reject(new Error('Unable to load config for NODE_ENV=' + envVal));
     }
 
     // Check that our url is valid
     if (!validator.isURL(config.url, { protocols: ['http', 'https'], require_protocol: true })) {
         errors.logError(new Error('Your site url in config.js is invalid.'), config.url, 'Please make sure this is a valid url before restarting');
 
-        return when.reject(new Error('invalid site url'));
+        return Promise.reject(new Error('invalid site url'));
     }
 
     parsedUrl = url.parse(config.url || 'invalid', false, true);
@@ -93,14 +92,14 @@ function validateConfigEnvironment() {
     if (/\/ghost(\/|$)/.test(parsedUrl.pathname)) {
         errors.logError(new Error('Your site url in config.js cannot contain a subdirectory called ghost.'), config.url, 'Please rename the subdirectory before restarting');
 
-        return when.reject(new Error('ghost subdirectory not allowed'));
+        return Promise.reject(new Error('ghost subdirectory not allowed'));
     }
 
     // Check that we have database values
     if (!config.database || !config.database.client) {
         errors.logError(new Error('Your database configuration in config.js is invalid.'), JSON.stringify(config.database), 'Please make sure this is a valid Bookshelf database configuration');
 
-        return when.reject(new Error('invalid database configuration'));
+        return Promise.reject(new Error('invalid database configuration'));
     }
 
     hasHostAndPort = config.server && !!config.server.host && !!config.server.port;
@@ -110,33 +109,32 @@ function validateConfigEnvironment() {
     if (!config.server || !(hasHostAndPort || hasSocket)) {
         errors.logError(new Error('Your server values (socket, or host and port) in config.js are invalid.'), JSON.stringify(config.server), 'Please provide them before restarting.');
 
-        return when.reject(new Error('invalid server configuration'));
+        return Promise.reject(new Error('invalid server configuration'));
     }
 
-    return when.resolve(config);
+    return Promise.resolve(config);
 }
 
 function loadConfig(configFilePath) {
-    var loaded = when.defer(),
-        pendingConfig;
-
-    // Allow config file path to be taken from, in order of importance:
-    // environment process, passed in value, default location
     configFile = process.env.GHOST_CONFIG || configFilePath || config.paths.config;
 
     /* Check for config file and copy from config.example.js
         if one doesn't exist. After that, start the server. */
-    fs.exists(configFile, function checkConfig(configExists) {
-        if (!configExists) {
-            pendingConfig = writeConfigFile();
-        }
+    return new Promise(function (resolve, reject) {
+        fs.exists(configFile, function (exists) {
+            var pendingConfig;
 
-        when(pendingConfig).then(validateConfigEnvironment).then(function (rawConfig) {
-            return config.init(rawConfig).then(loaded.resolve);
-        }).catch(loaded.reject);
+            if (!exists) {
+                pendingConfig = writeConfigFile();
+            }
+
+            Promise.resolve(pendingConfig)
+                .then(validateConfigEnvironment)
+                .then(function (rawConfig) {
+                    resolve(config.init(rawConfig));
+                }).catch(reject);
+        });
     });
-
-    return loaded.promise;
 }
 
 module.exports = loadConfig;
diff --git a/core/index.js b/core/index.js
index 3f2b8dddb0..66f4471918 100644
--- a/core/index.js
+++ b/core/index.js
@@ -2,33 +2,17 @@
 // Orchestrates the loading of Ghost
 // When run from command line.
 
-var when      = require('when'),
-    bootstrap = require('./bootstrap'),
+var bootstrap = require('./bootstrap'),
     server    = require('./server');
 
 process.env.NODE_ENV = process.env.NODE_ENV || 'development';
 
 function makeGhost(options) {
-    var deferred = when.defer();
-
     options = options || {};
 
-    bootstrap(options.config).then(function () {
-        try {
-            return server(options.app)
-                .then(deferred.resolve)
-                    .catch(function (err) {
-                    // We don't return the rejected promise to stop
-                    // the propagation of the rejection and just
-                    // allow the user to manage what to do.
-                    deferred.reject(err);
-                });
-        } catch (e) {
-            deferred.reject(e);
-        }
-    }).catch(deferred.reject);
-
-    return deferred.promise;
+    return bootstrap(options.config).then(function () {
+        return server(options.app);
+    });
 }
 
 module.exports = makeGhost;
diff --git a/core/server/GhostServer.js b/core/server/GhostServer.js
index 4866366cd9..98eea8a787 100644
--- a/core/server/GhostServer.js
+++ b/core/server/GhostServer.js
@@ -1,4 +1,4 @@
-var when = require('when'),
+var Promise = require('bluebird'),
     fs = require('fs'),
     semver = require('semver'),
     packageInfo = require('../../package.json'),
@@ -88,54 +88,59 @@ GhostServer.prototype.logUpgradeWarning = function () {
 
 // Starts the ghost server listening on the configured port
 GhostServer.prototype.start = function () {
+    var self = this;
+
     // ## Start Ghost App
-    var deferred  = when.defer();
-    if (config.getSocket()) {
-        // Make sure the socket is gone before trying to create another
-        try {
-            fs.unlinkSync(config.getSocket());
-        } catch (e) {
-            // We can ignore this.
+    return new Promise(function (resolve) {
+        if (config.getSocket()) {
+            // Make sure the socket is gone before trying to create another
+            try {
+                fs.unlinkSync(config.getSocket());
+            } catch (e) {
+                // We can ignore this.
+            }
+
+            self.httpServer = self.app.listen(
+                config.getSocket()
+            );
+
+            fs.chmod(config.getSocket(), '0660');
+
+        } else {
+            self.httpServer = self.app.listen(
+                config.server.port,
+                config.server.host
+            );
         }
 
-        this.httpServer = this.app.listen(
-            config.getSocket()
-        );
-        fs.chmod(config.getSocket(), '0660');
-
-    } else {
-        this.httpServer = this.app.listen(
-            config.server.port,
-            config.server.host
-        );
-    }
-
-    this.httpServer.on('connection', this.connection.bind(this));
-    this.httpServer.on('listening', function () {
-        this.logStartMessages();
-        clearTimeout(this.upgradeWarning);
-        deferred.resolve(this);
-    }.bind(this));
-    return deferred.promise;
+        self.httpServer.on('connection', self.connection.bind(self));
+        self.httpServer.on('listening', function () {
+            self.logStartMessages();
+            clearTimeout(self.upgradeWarning);
+            resolve(self);
+        });
+    });
 };
 
 // Returns a promise that will be fulfilled when the server stops.
 // If the server has not been started, the promise will be fulfilled
 // immediately
 GhostServer.prototype.stop = function () {
-    var deferred = when.defer();
+    var self = this;
 
-    if (this.httpServer === null) {
-        deferred.resolve(this);
-    } else {
-        this.httpServer.close(function () {
-            this.httpServer = null;
-            this.logShutdownMessages();
-            deferred.resolve(this);
-        }.bind(this));
-        this.closeConnections();
-    }
-    return deferred.promise;
+    return new Promise(function (resolve) {
+        if (self.httpServer === null) {
+            resolve(self);
+        } else {
+            self.httpServer.close(function () {
+                self.httpServer = null;
+                self.logShutdownMessages();
+                resolve(self);
+            });
+
+            self.closeConnections();
+        }
+    });
 };
 
 // Restarts the ghost application
@@ -146,8 +151,8 @@ GhostServer.prototype.restart = function () {
 // To be called after `stop`
 GhostServer.prototype.hammertime = function () {
     console.log('Can\'t touch this'.green);
-    return this;
+
+    return Promise.resolve(this);
 };
 
 module.exports = GhostServer;
-
diff --git a/core/server/api/authentication.js b/core/server/api/authentication.js
index de4df0b270..6e61b431fe 100644
--- a/core/server/api/authentication.js
+++ b/core/server/api/authentication.js
@@ -5,7 +5,7 @@ var _                = require('lodash'),
     globalUtils      = require('../utils'),
     utils            = require('./utils'),
     users            = require('./users'),
-    when             = require('when'),
+    Promise          = require('bluebird'),
     errors           = require('../errors'),
     config           = require('../config'),
     authentication;
@@ -31,7 +31,7 @@ authentication = {
             var setup = result.setup[0].status;
 
             if (!setup) {
-                return when.reject(new errors.NoPermissionError('Setup must be completed before making this request.'));
+                return Promise.reject(new errors.NoPermissionError('Setup must be completed before making this request.'));
             }
 
             return utils.checkObject(object, 'passwordreset');
@@ -39,13 +39,10 @@ authentication = {
             if (checkedPasswordReset.passwordreset[0].email) {
                 email = checkedPasswordReset.passwordreset[0].email;
             } else {
-                return when.reject(new errors.BadRequestError('No email provided.'));
+                return Promise.reject(new errors.BadRequestError('No email provided.'));
             }
 
-            return users.read({ context: {internal: true}, email: email, status: 'active' }).then(function (foundUser) {
-                if (!foundUser) {
-                    when.reject(new errors.NotFound('Invalid email address'));
-                }
+            return users.read({ context: {internal: true}, email: email, status: 'active' }).then(function () {
                 return settings.read({context: {internal: true}, key: 'dbHash'});
             }).then(function (response) {
                 var dbHash = response.settings[0].value;
@@ -69,9 +66,9 @@ authentication = {
                 };
                 return mail.send(payload, {context: {internal: true}});
             }).then(function () {
-                return when.resolve({passwordreset: [{message: 'Check your email for further instructions.'}]});
-            }).otherwise(function (error) {
-                return when.reject(error);
+                return Promise.resolve({passwordreset: [{message: 'Check your email for further instructions.'}]});
+            }).catch(function (error) {
+                return Promise.reject(error);
             });
         });
     },
@@ -91,7 +88,7 @@ authentication = {
             var setup = result.setup[0].status;
 
             if (!setup) {
-                return when.reject(new errors.NoPermissionError('Setup must be completed before making this request.'));
+                return Promise.reject(new errors.NoPermissionError('Setup must be completed before making this request.'));
             }
 
             return utils.checkObject(object, 'passwordreset');
@@ -104,9 +101,9 @@ authentication = {
                 var dbHash = response.settings[0].value;
                 return dataProvider.User.resetPassword(resetToken, newPassword, ne2Password, dbHash);
             }).then(function () {
-                return when.resolve({passwordreset: [{message: 'Password changed successfully.'}]});
-            }).otherwise(function (error) {
-                return when.reject(new errors.UnauthorizedError(error.message));
+                return Promise.resolve({passwordreset: [{message: 'Password changed successfully.'}]});
+            }).catch(function (error) {
+                return Promise.reject(new errors.UnauthorizedError(error.message));
             });
         });
     },
@@ -127,7 +124,7 @@ authentication = {
             var setup = result.setup[0].status;
 
             if (!setup) {
-                return when.reject(new errors.NoPermissionError('Setup must be completed before making this request.'));
+                return Promise.reject(new errors.NoPermissionError('Setup must be completed before making this request.'));
             }
 
             return utils.checkObject(object, 'invitation');
@@ -144,9 +141,9 @@ authentication = {
             }).then(function (user) {
                 return dataProvider.User.edit({name: name, email: email}, {id: user.id});
             }).then(function () {
-                return when.resolve({invitation: [{message: 'Invitation accepted.'}]});
-            }).otherwise(function (error) {
-                return when.reject(new errors.UnauthorizedError(error.message));
+                return Promise.resolve({invitation: [{message: 'Invitation accepted.'}]});
+            }).catch(function (error) {
+                return Promise.reject(new errors.UnauthorizedError(error.message));
             });
         });
     },
@@ -156,9 +153,9 @@ authentication = {
                 qb.whereIn('status', ['active', 'warn-1', 'warn-2', 'warn-3', 'warn-4', 'locked']);
             }).fetch().then(function (users) {
                 if (users) {
-                    return when.resolve({ setup: [{status: true}]});
+                    return Promise.resolve({ setup: [{status: true}]});
                 } else {
-                    return when.resolve({ setup: [{status: false}]});
+                    return Promise.resolve({ setup: [{status: false}]});
                 }
             });
     },
@@ -171,7 +168,7 @@ authentication = {
             var setup = result.setup[0].status;
 
             if (setup) {
-                return when.reject(new errors.NoPermissionError('Setup has already been completed.'));
+                return Promise.reject(new errors.NoPermissionError('Setup has already been completed.'));
             }
 
             return utils.checkObject(object, 'setup');
@@ -226,7 +223,7 @@ authentication = {
                     }]
                 };
 
-            return mail.send(payload, {context: {internal: true}}).otherwise(function (error) {
+            return mail.send(payload, {context: {internal: true}}).catch(function (error) {
                 errors.logError(
                     error.message,
                     "Unable to send welcome email, your blog will continue to function.",
@@ -235,7 +232,7 @@ authentication = {
             });
 
         }).then(function () {
-            return when.resolve({ users: [setupUser]});
+            return Promise.resolve({ users: [setupUser]});
         });
     }
 };
diff --git a/core/server/api/db.js b/core/server/api/db.js
index c22064d7e6..b13e90c93b 100644
--- a/core/server/api/db.js
+++ b/core/server/api/db.js
@@ -4,8 +4,7 @@ var dataExport       = require('../data/export'),
     dataImport       = require('../data/import'),
     dataProvider     = require('../models'),
     fs               = require('fs-extra'),
-    when             = require('when'),
-    nodefn           = require('when/node'),
+    Promise          = require('bluebird'),
     _                = require('lodash'),
     path             = require('path'),
     errors           = require('../../server/errors'),
@@ -41,14 +40,14 @@ db = {
 
         // Export data, otherwise send error 500
         return canThis(options.context).exportContent.db().then(function () {
-            return dataExport().then(function (exportedData) {
-                return when.resolve({ db: [exportedData] });
-            }).otherwise(function (error) {
-                return when.reject(new errors.InternalServerError(error.message || error));
+                return dataExport().then(function (exportedData) {
+                    return { db: [exportedData] };
+                }).catch(function (error) {
+                    return Promise.reject(new errors.InternalServerError(error.message || error));
+                });
+            }, function () {
+                return Promise.reject(new errors.NoPermissionError('You do not have permission to export data. (no rights)'));
             });
-        }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to export data. (no rights)'));
-        });
     },
     /**
      * ### Import Content
@@ -67,16 +66,16 @@ db = {
 
         return canThis(options.context).importContent.db().then(function () {
             if (!options.importfile || !options.importfile.type || !options.importfile.path) {
-                return when.reject(new errors.NoPermissionError('Please select a file to import.'));
+                return Promise.reject(new errors.NoPermissionError('Please select a file to import.'));
             }
 
             type = options.importfile.type;
             ext = path.extname(options.importfile.name).toLowerCase();
             filepath = options.importfile.path;
 
-            return when(isValidFile(ext)).then(function (result) {
+            return Promise.resolve(isValidFile(ext)).then(function (result) {
                 if (!result) {
-                    return when.reject(new errors.UnsupportedMediaTypeError('Please select a .json file to import.'));
+                    return Promise.reject(new errors.UnsupportedMediaTypeError('Please select a .json file to import.'));
                 }
             }).then(function () {
                 return api.settings.read(
@@ -84,12 +83,12 @@ db = {
                 ).then(function (response) {
                     var setting = response.settings[0];
 
-                    return when(setting.value);
+                    return setting.value;
                 });
             }).then(function (version) {
                 databaseVersion = version;
                 // Read the file contents
-                return nodefn.call(fs.readFile, filepath);
+                return Promise.promisify(fs.readFile)(filepath);
             }).then(function (fileContents) {
                 var importData;
 
@@ -103,11 +102,11 @@ db = {
                     }
                 } catch (e) {
                     errors.logError(e, 'API DB import content', 'check that the import file is valid JSON.');
-                    return when.reject(new errors.BadRequest('Failed to parse the import JSON file'));
+                    return Promise.reject(new errors.BadRequest('Failed to parse the import JSON file'));
                 }
 
                 if (!importData.meta || !importData.meta.version) {
-                    return when.reject(
+                    return Promise.reject(
                         new errors.ValidationError('Import data does not specify version', 'meta.version')
                     );
                 }
@@ -115,16 +114,14 @@ db = {
                 // Import for the current version
                 return dataImport(databaseVersion, importData);
 
-            }).then(function importSuccess() {
-                return api.settings.updateSettingsCache();
-            }).then(function () {
-                return when.resolve({ db: [] });
-            }).finally(function () {
+            }).then(api.settings.updateSettingsCache)
+            .return({ db: [] })
+            .finally(function () {
                 // Unlink the file after import
-                return nodefn.call(fs.unlink, filepath);
+                return Promise.promisify(fs.unlink)(filepath);
             });
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to import data. (no rights)'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to import data. (no rights)'));
         });
     },
     /**
@@ -139,14 +136,13 @@ db = {
         options = options || {};
 
         return canThis(options.context).deleteAllContent.db().then(function () {
-            return when(dataProvider.deleteAllContent())
-                .then(function () {
-                    return when.resolve({ db: [] });
-                }, function (error) {
-                    return when.reject(new errors.InternalServerError(error.message || error));
+            return Promise.resolve(dataProvider.deleteAllContent())
+                .return({ db: [] })
+                .catch(function (error) {
+                    return Promise.reject(new errors.InternalServerError(error.message || error));
                 });
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to export data. (no rights)'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to export data. (no rights)'));
         });
     }
 };
diff --git a/core/server/api/index.js b/core/server/api/index.js
index 81efc15a13..359af6c31f 100644
--- a/core/server/api/index.js
+++ b/core/server/api/index.js
@@ -5,7 +5,7 @@
 // from a theme, an app, or from an external app, you'll use the Ghost JSON API to do so.
 
 var _              = require('lodash'),
-    when           = require('when'),
+    Promise        = require('bluebird'),
     config         = require('../config'),
     // Include Endpoints
     db             = require('./db'),
@@ -90,7 +90,7 @@ cacheInvalidationHeader = function (req, result) {
         }
     }
 
-    return when(cacheInvalidate);
+    return Promise.resolve(cacheInvalidate);
 };
 
 /**
@@ -122,7 +122,7 @@ locationHeader = function (req, result) {
         }
     }
 
-    return when(location);
+    return Promise.resolve(location);
 };
 
 /**
@@ -219,7 +219,7 @@ addHeaders = function (apiMethod, req, res, result) {
         ops.push(contentDisposition);
     }
 
-    return when.all(ops);
+    return Promise.all(ops);
 };
 
 /**
diff --git a/core/server/api/mail.js b/core/server/api/mail.js
index ede252eb2f..545a0d4977 100644
--- a/core/server/api/mail.js
+++ b/core/server/api/mail.js
@@ -1,7 +1,7 @@
 // # Mail API
 // API for sending Mail
 var _            = require('lodash'),
-    when         = require('when'),
+    Promise      = require('bluebird'),
     config       = require('../config'),
     canThis      = require('../permissions').canThis,
     errors       = require('../errors'),
@@ -42,12 +42,12 @@ mail = {
                     };
                     return object;
                 })
-                .otherwise(function (error) {
-                    return when.reject(new errors.EmailError(error.message));
+                .catch(function (error) {
+                    return Promise.reject(new errors.EmailError(error.message));
                 });
 
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to send mail.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to send mail.'));
         });
     },
 
@@ -73,7 +73,7 @@ mail = {
                 return mail.send(payload, options);
             });
         }, function () {
-            return when.reject(new errors.NotFoundError('Could not find the current user'));
+            return Promise.reject(new errors.NotFoundError('Could not find the current user'));
         });
     },
 
@@ -95,7 +95,7 @@ mail = {
         _.templateSettings.interpolate = /{{([\s\S]+?)}}/g;
 
         //read the proper email body template
-        return when.promise(function (resolve, reject) {
+        return new Promise(function (resolve, reject) {
             fs.readFile(templatesDir + '/' + options.template + '.html', {encoding: 'utf8'}, function (err, fileContent) {
                 if (err) {
                     reject(err);
diff --git a/core/server/api/notifications.js b/core/server/api/notifications.js
index 649e0bf718..29a07a4f34 100644
--- a/core/server/api/notifications.js
+++ b/core/server/api/notifications.js
@@ -1,6 +1,6 @@
 // # Notifications API
 // RESTful API for creating notifications
-var when               = require('when'),
+var Promise            = require('bluebird'),
     _                  = require('lodash'),
     canThis            = require('../permissions').canThis,
     errors             = require('../errors'),
@@ -26,9 +26,9 @@ notifications = {
      */
     browse: function browse(options) {
         return canThis(options.context).browse.notification().then(function () {
-            return when({ 'notifications': notificationsStore });
+            return { 'notifications': notificationsStore };
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to browse notifications.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to browse notifications.'));
         });
     },
 
@@ -69,10 +69,10 @@ notifications = {
                     addedNotifications.push(notification);
                 });
 
-                return when({ notifications: addedNotifications});
+                return { notifications: addedNotifications };
             });
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to add notifications.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to add notifications.'));
         });
     },
 
@@ -90,21 +90,21 @@ notifications = {
             });
 
             if (notification && !notification.dismissible) {
-                return when.reject(
+                return Promise.reject(
                     new errors.NoPermissionError('You do not have permission to dismiss this notification.')
                 );
             }
 
             if (!notification) {
-                return when.reject(new errors.NotFoundError('Notification does not exist.'));
+                return Promise.reject(new errors.NotFoundError('Notification does not exist.'));
             }
 
             notificationsStore = _.reject(notificationsStore, function (element) {
                 return element.id === parseInt(options.id, 10);
             });
-            return when({notifications: [notification]});
+            return { notifications: [notification] };
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to destroy notifications.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to destroy notifications.'));
         });
     },
 
@@ -119,9 +119,10 @@ notifications = {
         return canThis(options.context).destroy.notification().then(function () {
             notificationsStore = [];
             notificationCounter = 0;
-            return when(notificationsStore);
+
+            return notificationsStore;
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to destroy notifications.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to destroy notifications.'));
         });
     }
 };
diff --git a/core/server/api/posts.js b/core/server/api/posts.js
index f6cfcdb814..371b255f8a 100644
--- a/core/server/api/posts.js
+++ b/core/server/api/posts.js
@@ -1,6 +1,6 @@
 // # Posts API
 // RESTful API for the Post resource
-var when            = require('when'),
+var Promise         = require('bluebird'),
     _               = require('lodash'),
     dataProvider    = require('../models'),
     canThis         = require('../permissions').canThis,
@@ -88,8 +88,7 @@ posts = {
                 return { posts: [ result.toJSON() ]};
             }
 
-            return when.reject(new errors.NotFoundError('Post not found.'));
-
+            return Promise.reject(new errors.NotFoundError('Post not found.'));
         });
     },
 
@@ -122,10 +121,10 @@ posts = {
                     return { posts: [ post ]};
                 }
 
-                return when.reject(new errors.NotFoundError('Post not found.'));
+                return Promise.reject(new errors.NotFoundError('Post not found.'));
             });
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to edit this post.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to edit posts.'));
         });
     },
 
@@ -158,7 +157,7 @@ posts = {
                 return { posts: [ post ]};
             });
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to add posts.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to add posts.'));
         });
     },
 
@@ -188,7 +187,7 @@ posts = {
                 });
             });
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to remove posts.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to remove posts.'));
         });
     }
 
diff --git a/core/server/api/roles.js b/core/server/api/roles.js
index 9f8781b5d9..ea07821aec 100644
--- a/core/server/api/roles.js
+++ b/core/server/api/roles.js
@@ -1,6 +1,6 @@
 // # Roles API
 // RESTful API for the Role resource
-var when            = require('when'),
+var Promise         = require('bluebird'),
     _               = require('lodash'),
     canThis         = require('../permissions').canThis,
     dataProvider    = require('../models'),
@@ -45,12 +45,12 @@ roles = {
                                 return null;
                             }
                             return role;
-                        }, function () {
+                        }).catch(function () {
                             return null;
                         }));
                     });
 
-                    return when.all(permissionMap).then(function (resolved) {
+                    return Promise.all(permissionMap).then(function (resolved) {
                         return { roles: _.filter(resolved, function (role) {
                             return role !== null;
                         }) };
diff --git a/core/server/api/settings.js b/core/server/api/settings.js
index ae537b31e7..f7072f6268 100644
--- a/core/server/api/settings.js
+++ b/core/server/api/settings.js
@@ -2,7 +2,7 @@
 // RESTful API for the Setting resource
 var _            = require('lodash'),
     dataProvider = require('../models'),
-    when         = require('when'),
+    Promise      = require('bluebird'),
     config       = require('../config'),
     canThis      = require('../permissions').canThis,
     errors       = require('../errors'),
@@ -44,7 +44,7 @@ updateSettingsCache = function (settings) {
             settingsCache[key] = setting;
         });
 
-        return when(settingsCache);
+        return Promise.resolve(settingsCache);
     }
 
     return dataProvider.Settings.findAll()
@@ -206,14 +206,14 @@ populateDefaultSetting = function (key) {
         }).then(function () {
             // Get the result from the cache with permission checks
         });
-    }).otherwise(function (err) {
+    }).catch(function (err) {
         // Pass along NotFoundError
         if (typeof err === errors.NotFoundError) {
-            return when.reject(err);
+            return Promise.reject(err);
         }
 
         // TODO: Different kind of error?
-        return when.reject(new errors.NotFoundError('Problem finding setting: ' + key));
+        return Promise.reject(new errors.NotFoundError('Problem finding setting: ' + key));
     });
 };
 
@@ -227,13 +227,13 @@ populateDefaultSetting = function (key) {
 canEditAllSettings = function (settingsInfo, options) {
     var checkSettingPermissions = function (setting) {
             if (setting.type === 'core' && !(options.context && options.context.internal)) {
-                return when.reject(
+                return Promise.reject(
                     new errors.NoPermissionError('Attempted to access core setting from external request')
                 );
             }
 
             return canThis(options.context).edit.setting(setting.key).catch(function () {
-                return when.reject(new errors.NoPermissionError('You do not have permission to edit settings.'));
+                return Promise.reject(new errors.NoPermissionError('You do not have permission to edit settings.'));
             });
 
         },
@@ -251,7 +251,7 @@ canEditAllSettings = function (settingsInfo, options) {
             return checkSettingPermissions(setting);
         });
 
-    return when.all(checks);
+    return Promise.all(checks);
 };
 
 /**
@@ -281,7 +281,7 @@ settings = {
 
         // If there is no context, return only blog settings
         if (!options.context) {
-            return when(_.filter(result.settings, function (setting) { return setting.type === 'blog'; }));
+            return Promise.resolve(_.filter(result.settings, function (setting) { return setting.type === 'blog'; }));
         }
 
         // Otherwise return whatever this context is allowed to browse
@@ -312,19 +312,19 @@ settings = {
                 result[options.key] = setting;
 
                 if (setting.type === 'core' && !(options.context && options.context.internal)) {
-                    return when.reject(
+                    return Promise.reject(
                         new errors.NoPermissionError('Attempted to access core setting from external request')
                     );
                 }
 
                 if (setting.type === 'blog') {
-                    return when(settingsResult(result));
+                    return Promise.resolve(settingsResult(result));
                 }
 
                 return canThis(options.context).read.setting(options.key).then(function () {
                     return settingsResult(result);
                 }, function () {
-                    return when.reject(new errors.NoPermissionError('You do not have permission to read settings.'));
+                    return Promise.reject(new errors.NoPermissionError('You do not have permission to read settings.'));
                 });
             };
 
diff --git a/core/server/api/slugs.js b/core/server/api/slugs.js
index 2a723ebffc..ac1b8dc96a 100644
--- a/core/server/api/slugs.js
+++ b/core/server/api/slugs.js
@@ -3,7 +3,7 @@
 var canThis      = require('../permissions').canThis,
     dataProvider = require('../models'),
     errors       = require('../errors'),
-    when         = require('when'),
+    Promise      = require('bluebird'),
 
     slugs,
     allowedTypes;
@@ -35,25 +35,25 @@ slugs = {
 
         return canThis(options.context).generate.slug().then(function () {
             if (allowedTypes[options.type] === undefined) {
-                return when.reject(new errors.BadRequestError('Unknown slug type \'' + options.type + '\'.'));
+                return Promise.reject(new errors.BadRequestError('Unknown slug type \'' + options.type + '\'.'));
             }
 
             return dataProvider.Base.Model.generateSlug(allowedTypes[options.type], options.name, {status: 'all'}).then(function (slug) {
                 if (!slug) {
-                    return when.reject(new errors.InternalServerError('Could not generate slug.'));
+                    return Promise.reject(new errors.InternalServerError('Could not generate slug.'));
                 }
 
                 return { slugs: [{ slug: slug }] };
             });
         }).catch(function (err) {
             if (err) {
-                return when.reject(err);
+                return Promise.reject(err);
             }
 
-            return when.reject(new errors.NoPermissionError('You do not have permission to generate a slug.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to generate a slug.'));
         });
     }
 
 };
 
-module.exports = slugs;
\ No newline at end of file
+module.exports = slugs;
diff --git a/core/server/api/tags.js b/core/server/api/tags.js
index ba29198a57..b49bc59aa6 100644
--- a/core/server/api/tags.js
+++ b/core/server/api/tags.js
@@ -1,6 +1,6 @@
 // # Tag API
 // RESTful API for the Tag resource
-var when       = require('when'),
+var Promise    = require('bluebird'),
     canThis    = require('../permissions').canThis,
     dataProvider = require('../models'),
     errors     = require('../errors'),
@@ -24,9 +24,9 @@ tags = {
             });
 
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to browse tags.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to browse tags.'));
         });
     }
 };
 
-module.exports = tags;
\ No newline at end of file
+module.exports = tags;
diff --git a/core/server/api/themes.js b/core/server/api/themes.js
index f007cab45e..e3f23c812e 100644
--- a/core/server/api/themes.js
+++ b/core/server/api/themes.js
@@ -1,12 +1,11 @@
 // # Themes API
 // RESTful API for Themes
-var when               = require('when'),
+var Promise            = require('bluebird'),
     _                  = require('lodash'),
     canThis            = require('../permissions').canThis,
     config             = require('../config'),
     errors             = require('../errors'),
     settings           = require('./settings'),
-    when               = require('when'),
     themes;
 
 /**
@@ -25,7 +24,7 @@ themes = {
         options = options || {};
 
         return canThis(options.context).browse.theme().then(function () {
-            return when.all([
+            return Promise.all([
                 settings.read({key: 'activeTheme', context: {internal: true}}),
                 config.paths.availableThemes
             ]).then(function (result) {
@@ -57,7 +56,7 @@ themes = {
                 return { themes: themes };
             });
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to browse themes.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to browse themes.'));
         });
     },
 
@@ -73,7 +72,7 @@ themes = {
 
         // Check whether the request is properly formatted.
         if (!_.isArray(object.themes)) {
-            return when.reject({type: 'BadRequest', message: 'Invalid request.'});
+            return Promise.reject({type: 'BadRequest', message: 'Invalid request.'});
         }
 
         themeName = object.themes[0].uuid;
@@ -88,7 +87,7 @@ themes = {
                 });
 
                 if (!theme) {
-                    return when.reject(new errors.BadRequestError('Theme does not exist.'));
+                    return Promise.reject(new errors.BadRequestError('Theme does not exist.'));
                 }
 
                 // Activate the theme
@@ -100,7 +99,7 @@ themes = {
                 });
             });
         }, function () {
-            return when.reject(new errors.NoPermissionError('You do not have permission to edit themes.'));
+            return Promise.reject(new errors.NoPermissionError('You do not have permission to edit themes.'));
         });
     }
 };
diff --git a/core/server/api/upload.js b/core/server/api/upload.js
index 4b7c15c66c..5429fe266f 100644
--- a/core/server/api/upload.js
+++ b/core/server/api/upload.js
@@ -1,14 +1,11 @@
-var when    = require('when'),
+var Promise = require('bluebird'),
     path    = require('path'),
-    nodefn  = require('when/node'),
     fs      = require('fs-extra'),
     storage = require('../storage'),
     errors  = require('../errors'),
 
     upload;
 
-
-
 function isImage(type, ext) {
     if ((type === 'image/jpeg' || type === 'image/png' || type === 'image/gif' || type === 'image/svg+xml')
             && (ext === '.jpg' || ext === '.jpeg' || ext === '.png' || ext === '.gif' || ext === '.svg' || ext === '.svgz')) {
@@ -17,7 +14,6 @@ function isImage(type, ext) {
     return false;
 }
 
-
 /**
  * ## Upload API Methods
  *
@@ -32,33 +28,33 @@ upload = {
      * @param {{context}} options
      * @returns {Promise} Success
      */
-    'add': function (options) {
+    add: function (options) {
         var store = storage.get_storage(),
             type,
             ext,
             filepath;
 
         if (!options.uploadimage || !options.uploadimage.type || !options.uploadimage.path) {
-            return when.reject(new errors.NoPermissionError('Please select an image.'));
+            return Promise.reject(new errors.NoPermissionError('Please select an image.'));
         }
 
         type = options.uploadimage.type;
         ext = path.extname(options.uploadimage.name).toLowerCase();
         filepath = options.uploadimage.path;
 
-        return when(isImage(type, ext)).then(function (result) {
+        return Promise.resolve(isImage(type, ext)).then(function (result) {
             if (!result) {
-                return when.reject(new errors.UnsupportedMediaTypeError('Please select a valid image.'));
+                return Promise.reject(new errors.UnsupportedMediaTypeError('Please select a valid image.'));
             }
         }).then(function () {
             return store.save(options.uploadimage);
         }).then(function (url) {
-            return when.resolve(url);
+            return url;
         }).finally(function () {
             // Remove uploaded file from tmp location
-            return nodefn.call(fs.unlink, filepath);
+            return Promise.promisify(fs.unlink)(filepath);
         });
     }
 };
 
-module.exports = upload;
\ No newline at end of file
+module.exports = upload;
diff --git a/core/server/api/users.js b/core/server/api/users.js
index 9397dd8b85..23f6e5612a 100644
--- a/core/server/api/users.js
+++ b/core/server/api/users.js
@@ -1,6 +1,6 @@
 // # Users API
 // RESTful API for the User resource
-var when            = require('when'),
+var Promise         = require('bluebird'),
     _               = require('lodash'),
     dataProvider    = require('../models'),
     settings        = require('./settings'),
@@ -26,7 +26,7 @@ function prepareInclude(include) {
 sendInviteEmail = function sendInviteEmail(user) {
     var emailData;
 
-    return when.join(
+    return Promise.join(
         users.read({'id': user.created_by}),
         settings.read({'key': 'title'}),
         settings.read({context: {internal: true}, key: 'dbHash'})
@@ -114,7 +114,7 @@ users = {
                 return { users: [result.toJSON()] };
             }
 
-            return when.reject(new errors.NotFoundError('User not found.'));
+            return Promise.reject(new errors.NotFoundError('User not found.'));
         });
     },
 
@@ -143,7 +143,7 @@ users = {
                             return { users: [result.toJSON()]};
                         }
 
-                        return when.reject(new errors.NotFoundError('User not found.'));
+                        return Promise.reject(new errors.NotFoundError('User not found.'));
                     });
             };
 
@@ -160,7 +160,7 @@ users = {
 
                         if (roleId !== contextRoleId &&
                                 parseInt(options.id, 10) === parseInt(options.context.user, 10)) {
-                            return when.reject(new errors.NoPermissionError('You cannot change your own role.'));
+                            return Promise.reject(new errors.NoPermissionError('You cannot change your own role.'));
                         } else if (roleId !== contextRoleId) {
                             return dataProvider.User.findOne({role: 'Owner'}).then(function (result) {
                                 if (parseInt(result.id, 10) !== parseInt(options.id, 10)) {
@@ -168,7 +168,7 @@ users = {
                                         return editOperation();
                                     });
                                 } else {
-                                    return when.reject(new errors.NoPermissionError('There has to be one owner.'));
+                                    return Promise.reject(new errors.NoPermissionError('There has to be one owner.'));
                                 }
                             });
                         }
@@ -208,7 +208,7 @@ users = {
                     newUser.password = globalUtils.uid(50);
                     newUser.status = 'invited';
                 } else {
-                    return when.reject(new errors.BadRequestError('No email provided.'));
+                    return Promise.reject(new errors.BadRequestError('No email provided.'));
                 }
 
                 return dataProvider.User.getByEmail(
@@ -221,7 +221,7 @@ users = {
                         if (foundUser.get('status') === 'invited' || foundUser.get('status') === 'invited-pending') {
                             return foundUser;
                         } else {
-                            return when.reject(new errors.BadRequestError('User is already registered.'));
+                            return Promise.reject(new errors.BadRequestError('User is already registered.'));
                         }
                     }
                 }).then(function (invitedUser) {
@@ -237,7 +237,7 @@ users = {
                         });
                     }
                 }).then(function () {
-                    return when.resolve({users: [user]});
+                    return Promise.resolve({users: [user]});
                 }).catch(function (error) {
                     if (error && error.type === 'EmailError') {
                         error.message = 'Error sending email: ' + error.message + ' Please check your email settings and resend the invitation.';
@@ -250,7 +250,7 @@ users = {
                             });
                         });
                     }
-                    return when.reject(error);
+                    return Promise.reject(error);
                 });
             };
 
@@ -262,7 +262,7 @@ users = {
                     // Make sure user is allowed to add a user with this role
                     return dataProvider.Role.findOne({id: roleId}).then(function (role) {
                         if (role.get('name') === 'Owner') {
-                            return when.reject(new errors.NoPermissionError('Not allowed to create an owner user.'));
+                            return Promise.reject(new errors.NoPermissionError('Not allowed to create an owner user.'));
                         }
 
                         return canThis(options.context).assign.role(role);
@@ -300,7 +300,7 @@ users = {
                 }).then(function () {
                     return result;
                 }, function (error) {
-                    return when.reject(new errors.InternalServerError(error));
+                    return Promise.reject(new errors.InternalServerError(error));
                 });
             }, function (error) {
                 return errors.handleAPIError(error);
@@ -327,9 +327,9 @@ users = {
             ne2Password = checkedPasswordReset.password[0].ne2Password;
 
             return dataProvider.User.changePassword(oldPassword, newPassword, ne2Password, options).then(function () {
-                return when.resolve({password: [{message: 'Password changed successfully.'}]});
+                return Promise.resolve({password: [{message: 'Password changed successfully.'}]});
             }).catch(function (error) {
-                return when.reject(new errors.ValidationError(error.message));
+                return Promise.reject(new errors.ValidationError(error.message));
             });
         });
     },
@@ -343,9 +343,9 @@ users = {
         }).then(function () {
             return utils.checkObject(object, 'owner').then(function (checkedOwnerTransfer) {
                 return dataProvider.User.transferOwnership(checkedOwnerTransfer.owner[0], options).then(function (updatedUsers) {
-                    return when.resolve({ users: updatedUsers });
+                    return Promise.resolve({ users: updatedUsers });
                 }).catch(function (error) {
-                    return when.reject(new errors.ValidationError(error.message));
+                    return Promise.reject(new errors.ValidationError(error.message));
                 });
             });
         }).catch(function (error) {
diff --git a/core/server/api/utils.js b/core/server/api/utils.js
index 948adc060b..cfc77bc75d 100644
--- a/core/server/api/utils.js
+++ b/core/server/api/utils.js
@@ -1,6 +1,6 @@
 // # API Utils
 // Shared helpers for working with the API
-var when    = require('when'),
+var Promise = require('bluebird'),
     _       = require('lodash'),
     errors  = require('../errors'),
     utils;
@@ -27,8 +27,8 @@ utils = {
                 delete object.posts[0].author;
             }
         }
-        return when(object);
+        return Promise.resolve(object);
     }
 };
 
-module.exports = utils;
\ No newline at end of file
+module.exports = utils;
diff --git a/core/server/apps/dependencies.js b/core/server/apps/dependencies.js
index 843fade7c0..8a255309f6 100644
--- a/core/server/apps/dependencies.js
+++ b/core/server/apps/dependencies.js
@@ -2,7 +2,7 @@
 var _ = require('lodash'),
     fs = require('fs'),
     path = require('path'),
-    when = require('when'),
+    Promise = require('bluebird'),
     spawn = require('child_process').spawn,
     win32 = process.platform === 'win32';
 
@@ -11,32 +11,33 @@ function AppDependencies(appPath) {
 }
 
 AppDependencies.prototype.install = function installAppDependencies() {
-    var def = when.defer(),
-        spawnOpts;
+    var spawnOpts,
+        self = this;
 
-    fs.exists(path.join(this.appPath, 'package.json'), function (exists) {
-        if (!exists) {
-            // Nothing to do, resolve right away?
-            def.resolve();
-        } else {
-            // Run npm install in the app directory
-            spawnOpts = {
-                cwd: this.appPath
-            };
+    return new Promise(function (resolve, reject) {
+        fs.exists(path.join(self.appPath, 'package.json'), function (exists) {
+            if (!exists) {
+                // Nothing to do, resolve right away?
+                resolve();
+            }
+            else {
+                // Run npm install in the app directory
+                spawnOpts = {
+                    cwd: self.appPath
+                };
 
-            this.spawnCommand('npm', ['install', '--production'], spawnOpts)
-                .on('error', def.reject)
-                .on('exit', function (err) {
-                    if (err) {
-                        def.reject(err);
-                    }
+                self.spawnCommand('npm', ['install', '--production'], spawnOpts)
+                    .on('error', reject)
+                    .on('exit', function (err) {
+                        if (err) {
+                            reject(err);
+                        }
 
-                    def.resolve();
-                });
-        }
-    }.bind(this));
-
-    return def.promise;
+                        resolve();
+                    });
+            }
+        });
+    });
 };
 
 // Normalize a command across OS and spawn it; taken from yeoman/generator
@@ -49,4 +50,4 @@ AppDependencies.prototype.spawnCommand = function (command, args, opt) {
     return spawn(winCommand, winArgs, _.defaults({ stdio: 'inherit' }, opt));
 };
 
-module.exports = AppDependencies;
\ No newline at end of file
+module.exports = AppDependencies;
diff --git a/core/server/apps/index.js b/core/server/apps/index.js
index ab59e686e7..77d4cf6ba9 100644
--- a/core/server/apps/index.js
+++ b/core/server/apps/index.js
@@ -1,13 +1,12 @@
 
 var _           = require('lodash'),
-    when        = require('when'),
+    Promise     = require('bluebird'),
     errors      = require('../errors'),
     api         = require('../api'),
     loader      = require('./loader'),
     // Holds the available apps
     availableApps = {};
 
-
 function getInstalledApps() {
     return api.settings.read({context: {internal: true}, key: 'installedApps'}).then(function (response) {
         var installed = response.settings[0];
@@ -17,7 +16,7 @@ function getInstalledApps() {
         try {
             installed = JSON.parse(installed.value);
         } catch (e) {
-            return when.reject(e);
+            return Promise.reject(e);
         }
 
         return installed;
@@ -49,7 +48,8 @@ module.exports = {
                 'Your apps will not be loaded.',
                 'Check your settings table for typos in the activeApps value. It should look like: ["app-1", "app2"] (double quotes required).'
             );
-            return when.resolve();
+
+            return Promise.resolve();
         }
 
         // Grab all installed apps, install any not already installed that are in appsToLoad.
@@ -59,7 +59,7 @@ module.exports = {
                     // After loading the app, add it to our hash of loaded apps
                     loadedApps[name] = loadedApp;
 
-                    return when.resolve(loadedApp);
+                    return Promise.resolve(loadedApp);
                 },
                 loadPromises = _.map(appsToLoad, function (app) {
                     // If already installed, just activate the app
@@ -77,13 +77,13 @@ module.exports = {
                     });
                 });
 
-            return when.all(loadPromises).then(function () {
+            return Promise.all(loadPromises).then(function () {
                 // Save our installed apps to settings
                 return saveInstalledApps(_.keys(loadedApps));
             }).then(function () {
                 // Extend the loadedApps onto the available apps
                 _.extend(availableApps, loadedApps);
-            }).otherwise(function (err) {
+            }).catch(function (err) {
                 errors.logError(
                     err.message || err,
                     'The app will not be loaded',
@@ -93,4 +93,4 @@ module.exports = {
         });
     },
     availableApps: availableApps
-};
\ No newline at end of file
+};
diff --git a/core/server/apps/loader.js b/core/server/apps/loader.js
index 60af307faa..ca6d9bcf20 100644
--- a/core/server/apps/loader.js
+++ b/core/server/apps/loader.js
@@ -1,7 +1,7 @@
 
 var path = require('path'),
     _    = require('lodash'),
-    when = require('when'),
+    Promise = require('bluebird'),
     AppProxy = require('./proxy'),
     config = require('../config'),
     AppSandbox = require('./sandbox'),
@@ -64,9 +64,9 @@ loader = {
                 // Load app permissions
                 var perms = new AppPermissions(appPath);
 
-                return perms.read().otherwise(function (err) {
+                return perms.read().catch(function (err) {
                     // Provide a helpful error about which app
-                    return when.reject(new Error("Error loading app named " + name + "; problem reading permissions: " + err.message));
+                    return Promise.reject(new Error("Error loading app named " + name + "; problem reading permissions: " + err.message));
                 });
             })
             .then(function (appPerms) {
@@ -76,15 +76,13 @@ loader = {
 
                 // Check for an install() method on the app.
                 if (!_.isFunction(app.install)) {
-                    return when.reject(new Error("Error loading app named " + name + "; no install() method defined."));
+                    return Promise.reject(new Error("Error loading app named " + name + "; no install() method defined."));
                 }
 
                 // Run the app.install() method
                 // Wrapping the install() with a when because it's possible
                 // to not return a promise from it.
-                return when(app.install(appProxy)).then(function () {
-                    return when.resolve(app);
-                });
+                return Promise.resolve(app.install(appProxy)).return(app);
             });
     },
 
@@ -99,16 +97,14 @@ loader = {
 
             // Check for an activate() method on the app.
             if (!_.isFunction(app.activate)) {
-                return when.reject(new Error("Error loading app named " + name + "; no activate() method defined."));
+                return Promise.reject(new Error("Error loading app named " + name + "; no activate() method defined."));
             }
 
             // Wrapping the activate() with a when because it's possible
             // to not return a promise from it.
-            return when(app.activate(appProxy)).then(function () {
-                return when.resolve(app);
-            });
+            return Promise.resolve(app.activate(appProxy)).return(app);
         });
     }
 };
 
-module.exports = loader;
\ No newline at end of file
+module.exports = loader;
diff --git a/core/server/apps/permissions.js b/core/server/apps/permissions.js
index 25202d6144..d287b98a8c 100644
--- a/core/server/apps/permissions.js
+++ b/core/server/apps/permissions.js
@@ -1,6 +1,6 @@
 
 var fs = require('fs'),
-    when = require('when'),
+    Promise = require('bluebird'),
     path = require('path'),
     parsePackageJson = require('../require-tree').parsePackageJson;
 
@@ -10,44 +10,35 @@ function AppPermissions(appPath) {
 }
 
 AppPermissions.prototype.read = function () {
-    var self = this,
-        def = when.defer();
+    var self = this;
 
-    this.checkPackageContentsExists()
-        .then(function (exists) {
+    return this.checkPackageContentsExists().then(function (exists) {
             if (!exists) {
                 // If no package.json, return default permissions
-                return def.resolve(AppPermissions.DefaultPermissions);
+                return Promise.resolve(AppPermissions.DefaultPermissions);
             }
 
             // Read and parse the package.json
-            self.getPackageContents()
-                .then(function (parsed) {
+            return self.getPackageContents().then(function (parsed) {
                     // If no permissions in the package.json then return the default permissions.
                     if (!(parsed.ghost && parsed.ghost.permissions)) {
-                        return def.resolve(AppPermissions.DefaultPermissions);
+                        return Promise.resolve(AppPermissions.DefaultPermissions);
                     }
 
                     // TODO: Validation on permissions object?
 
-                    def.resolve(parsed.ghost.permissions);
-                })
-                .otherwise(def.reject);
-        })
-        .otherwise(def.reject);
-
-    return def.promise;
+                    return Promise.resolve(parsed.ghost.permissions);
+                });
+        });
 };
 
 AppPermissions.prototype.checkPackageContentsExists = function () {
     // Mostly just broken out for stubbing in unit tests
-    var def = when.defer();
-
-    fs.exists(this.packagePath, function (exists) {
-        def.resolve(exists);
+    return new Promise(function (resolve) {
+        fs.exists(this.packagePath, function (exists) {
+            resolve(exists);
+        });
     });
-
-    return def.promise;
 };
 
 // Get the contents of the package.json in the appPath root
@@ -60,7 +51,7 @@ AppPermissions.prototype.getPackageContents = function () {
     return parsePackageJson(this.packagePath, messages)
         .then(function (parsed) {
             if (!parsed) {
-                return when.reject(new Error(messages.errors[0].message));
+                return Promise.reject(new Error(messages.errors[0].message));
             }
 
             return parsed;
@@ -72,4 +63,4 @@ AppPermissions.DefaultPermissions = {
     posts: ['browse', 'read']
 };
 
-module.exports = AppPermissions;
\ No newline at end of file
+module.exports = AppPermissions;
diff --git a/core/server/config/index.js b/core/server/config/index.js
index a76c547260..ccb8fc4cb9 100644
--- a/core/server/config/index.js
+++ b/core/server/config/index.js
@@ -4,7 +4,7 @@
 // All other files that need to reference config.js should use this file.
 
 var path          = require('path'),
-    when          = require('when'),
+    Promise       = require('bluebird'),
     url           = require('url'),
     _             = require('lodash'),
     knex          = require('knex'),
@@ -101,7 +101,7 @@ function initConfig(rawConfig) {
     // just the object appropriate for this NODE_ENV
     updateConfig(rawConfig);
 
-    return when.all([requireTree(ghostConfig.paths.themePath), requireTree(ghostConfig.paths.appPath)]).then(function (paths) {
+    return Promise.all([requireTree(ghostConfig.paths.themePath), requireTree(ghostConfig.paths.appPath)]).then(function (paths) {
         ghostConfig.paths.availableThemes = paths[0];
         ghostConfig.paths.availableApps = paths[1];
         return ghostConfig;
diff --git a/core/server/config/theme.js b/core/server/config/theme.js
index 23686ac396..89794414c6 100644
--- a/core/server/config/theme.js
+++ b/core/server/config/theme.js
@@ -1,7 +1,7 @@
 // Holds all theme configuration information
 // that as mostly used by templates and handlebar helpers.
 
-var when        = require('when'),
+var Promise = require('bluebird'),
 
 // Variables
     themeConfig = {};
@@ -18,7 +18,7 @@ function theme() {
 // tries to access the config() object before it is created.
 function update(settings, configUrl) {
     // TODO: Pass the context into this method instead of hard coding internal: true?
-    return when.all([
+    return Promise.all([
         settings.read('title'),
         settings.read('description'),
         settings.read('logo'),
@@ -30,7 +30,6 @@ function update(settings, configUrl) {
         themeConfig.description = globals[1].settings[0].value;
         themeConfig.logo = globals[2].settings[0] ? globals[2].settings[0].value : '';
         themeConfig.cover = globals[3].settings[0] ? globals[3].settings[0].value : '';
-        return;
     });
 }
 
diff --git a/core/server/controllers/admin.js b/core/server/controllers/admin.js
index 7f0fd2eaf9..134fc58e5a 100644
--- a/core/server/controllers/admin.js
+++ b/core/server/controllers/admin.js
@@ -1,5 +1,4 @@
 var _             = require('lodash'),
-    when          = require('when'),
     api           = require('../api'),
     errors        = require('../errors'),
     updateCheck   = require('../update-check'),
@@ -9,7 +8,7 @@ adminControllers = {
     // Route: index
     // Path: /ghost/
     // Method: GET
-    'index': function (req, res) {
+    index: function (req, res) {
         /*jslint unparam:true*/
 
         function renderIndex() {
@@ -20,7 +19,7 @@ adminControllers = {
             return updateCheck.showUpdateNotification();
         }).then(function (updateVersion) {
             if (!updateVersion) {
-                return when.resolve();
+                return;
             }
 
             var notification = {
diff --git a/core/server/controllers/frontend.js b/core/server/controllers/frontend.js
index f5a51cc96a..96025b67c7 100644
--- a/core/server/controllers/frontend.js
+++ b/core/server/controllers/frontend.js
@@ -8,8 +8,7 @@ var moment      = require('moment'),
     RSS         = require('rss'),
     _           = require('lodash'),
     url         = require('url'),
-    when        = require('when'),
-
+    Promise     = require('bluebird'),
     api         = require('../api'),
     config      = require('../config'),
     filters     = require('../../server/filters'),
@@ -84,9 +83,7 @@ function formatResponse(post) {
 
 function handleError(next) {
     return function (err) {
-        var e = new Error(err.message);
-        e.status = err.code;
-        return next(e);
+        return next(err);
     };
 }
 
@@ -152,7 +149,7 @@ frontendControllers = {
                     res.render(view, formatPageResponse(posts, page));
                 });
             });
-        }).otherwise(handleError(next));
+        }).catch(handleError(next));
     },
     'tag': function (req, res, next) {
         // Parse the page number
@@ -206,7 +203,7 @@ frontendControllers = {
                     res.render(view, result);
                 });
             });
-        }).otherwise(handleError(next));
+        }).catch(handleError(next));
     },
     'author': function (req, res, next) {
 
@@ -263,7 +260,7 @@ frontendControllers = {
                     res.render(view, result);
                 });
             });
-        }).otherwise(handleError(next));
+        }).catch(handleError(next));
     },
 
     'single': function (req, res, next) {
@@ -290,7 +287,7 @@ frontendControllers = {
                 // If there are still no matches then return.
                 if (staticPostPermalink.match(path) === false) {
                     // Reject promise chain with type 'NotFound'
-                    return when.reject(new errors.NotFoundError());
+                    return Promise.reject(new errors.NotFoundError());
                 }
 
                 permalink = staticPostPermalink;
@@ -324,7 +321,7 @@ frontendControllers = {
                     return res.redirect(config.paths.subdir + '/ghost/editor/' + post.id + '/');
                 } else if (params.edit !== undefined) {
                     // reject with type: 'NotFound'
-                    return when.reject(new errors.NotFoundError());
+                    return Promise.reject(new errors.NotFoundError());
                 }
 
                 setReqCtx(req, post);
@@ -380,7 +377,7 @@ frontendControllers = {
 
             return render();
 
-        }).otherwise(function (err) {
+        }).catch(function (err) {
             // If we've thrown an error message
             // of type: 'NotFound' then we found
             // no path match.
@@ -422,13 +419,13 @@ frontendControllers = {
             return res.redirect(baseUrl);
         }
 
-        return when.settle([
+        return Promise.all([
             api.settings.read('title'),
             api.settings.read('description'),
             api.settings.read('permalinks')
         ]).then(function (result) {
-
             var options = {};
+
             if (pageParam) { options.page = pageParam; }
             if (isTag()) { options.tag = slugParam; }
             if (isAuthor()) { options.author = slugParam; }
@@ -436,16 +433,14 @@ frontendControllers = {
             options.include = 'author,tags,fields';
 
             return api.posts.browse(options).then(function (page) {
-
-                var title = result[0].value.settings[0].value,
-                    description = result[1].value.settings[0].value,
-                    permalinks = result[2].value.settings[0],
+                var title = result[0].settings[0].value,
+                    description = result[1].settings[0].value,
+                    permalinks = result[2].settings[0],
                     majorMinor = /^(\d+\.)?(\d+)/,
                     trimmedVersion = res.locals.version,
                     siteUrl = config.urlFor('home', {secure: req.secure}, true),
                     feedUrl = config.urlFor('rss', {secure: req.secure}, true),
                     maxPage = page.meta.pagination.pages,
-                    feedItems = [],
                     feed;
 
                 trimmedVersion = trimmedVersion ? trimmedVersion.match(majorMinor)[0] : '?';
@@ -482,8 +477,7 @@ frontendControllers = {
 
                 filters.doFilter('prePostsRender', page.posts).then(function (posts) {
                     posts.forEach(function (post) {
-                        var deferred = when.defer(),
-                            item = {
+                        var item = {
                                 title: post.title,
                                 guid: post.uuid,
                                 url: config.urlFor('post', {post: post, permalinks: permalinks}, true),
@@ -499,25 +493,23 @@ frontendControllers = {
                             p1 = url.resolve(siteUrl, p1);
                             return "src='" + p1 + "' ";
                         });
+
                         //set a href to absolute url
                         content = content.replace(/href=["|'|\s]?([\w\/\?\$\.\+\-;%:@&=,_]+)["|'|\s]?/gi, function (match, p1) {
                             /*jslint unparam:true*/
                             p1 = url.resolve(siteUrl, p1);
                             return "href='" + p1 + "' ";
                         });
+
                         item.description = content;
                         feed.item(item);
-                        feedItems.push(deferred.promise);
-                        deferred.resolve();
                     });
-                });
-
-                when.all(feedItems).then(function () {
+                }).then(function () {
                     res.set('Content-Type', 'text/xml; charset=UTF-8');
                     res.send(feed.xml());
                 });
             });
-        }).otherwise(handleError(next));
+        }).catch(handleError(next));
     }
 };
 
diff --git a/core/server/data/export/index.js b/core/server/data/export/index.js
index a3b77e1318..09810ca97a 100644
--- a/core/server/data/export/index.js
+++ b/core/server/data/export/index.js
@@ -1,6 +1,5 @@
 var _           = require('lodash'),
-    when        = require('when'),
-
+    Promise     = require('bluebird'),
     versioning  = require('../versioning'),
     config      = require('../../config'),
     utils       = require('../utils'),
@@ -28,7 +27,7 @@ exportFileName = function () {
 };
 
 exporter = function () {
-    return when.join(versioning.getDatabaseVersion(), utils.getTables()).then(function (results) {
+    return Promise.join(versioning.getDatabaseVersion(), utils.getTables()).then(function (results) {
         var version = results[0],
             tables = results[1],
             selectOps = _.map(tables, function (name) {
@@ -37,7 +36,7 @@ exporter = function () {
                 }
             });
 
-        return when.all(selectOps).then(function (tableData) {
+        return Promise.all(selectOps).then(function (tableData) {
             var exportData = {
                 meta: {
                     exported_on: new Date().getTime(),
@@ -52,7 +51,7 @@ exporter = function () {
                 exportData.data[name] = tableData[i];
             });
 
-            return when.resolve(exportData);
+            return exportData;
         }).catch(function (err) {
             errors.logAndThrowError(err, 'Error exporting data', '');
         });
diff --git a/core/server/data/fixtures/index.js b/core/server/data/fixtures/index.js
index d7294c5544..8a9f7bbe10 100644
--- a/core/server/data/fixtures/index.js
+++ b/core/server/data/fixtures/index.js
@@ -5,8 +5,8 @@
 // rather than abstracted into a migration system. The upgrade function checks that its changes are safe before
 // making them.
 
-var when        = require('when'),
-    sequence    = require('when/sequence'),
+var Promise     = require('bluebird'),
+    sequence    = require('../../utils/sequence'),
     _           = require('lodash'),
     errors      = require('../../errors'),
     utils       = require('../../utils'),
@@ -101,7 +101,7 @@ populate = function () {
         });
     });
 
-    return when.all(ops).then(function () {
+    return Promise.all(ops).then(function () {
         return sequence(relations);
     }).then(function () {
         return permissions.populate(options);
@@ -150,7 +150,7 @@ to003 = function () {
     });
     ops.push(upgradeOp);
 
-    return when.all(ops).then(function () {
+    return Promise.all(ops).then(function () {
         return permissions.to003(options);
     }).then(function () {
         return convertAdminToOwner();
diff --git a/core/server/data/fixtures/permissions/index.js b/core/server/data/fixtures/permissions/index.js
index ebc4edfa13..c1dbe1d99f 100644
--- a/core/server/data/fixtures/permissions/index.js
+++ b/core/server/data/fixtures/permissions/index.js
@@ -1,7 +1,7 @@
 // # Permissions Fixtures
 // Sets up the permissions, and the default permissions_roles relationships
-var when        = require('when'),
-    sequence    = require('when/sequence'),
+var Promise     = require('bluebird'),
+    sequence    = require('../../../utils/sequence'),
     _           = require('lodash'),
     errors      = require('../../../errors'),
     models      = require('../../../models'),
@@ -52,7 +52,7 @@ addAllRolesPermissions = function () {
         ops.push(addRolesPermissionsForRole(roleName));
     });
 
-    return when.all(ops);
+    return Promise.all(ops);
 };
 
 
@@ -100,7 +100,7 @@ to003 = function (options) {
     });
 
     // Now we can perfom the normal populate
-    return when.all(ops).then(function () {
+    return Promise.all(ops).then(function () {
         return populate(options);
     });
 };
diff --git a/core/server/data/import/000.js b/core/server/data/import/000.js
index b80bdf5805..0054d25e67 100644
--- a/core/server/data/import/000.js
+++ b/core/server/data/import/000.js
@@ -1,7 +1,7 @@
-var when   = require('when'),
-    _      = require('lodash'),
-    models = require('../../models'),
-    utils  = require('./utils'),
+var Promise = require('bluebird'),
+    _       = require('lodash'),
+    models  = require('../../models'),
+    utils   = require('./utils'),
 
     Importer000;
 
@@ -23,17 +23,15 @@ Importer000.prototype.importData = function (data) {
     return this.canImport(data)
         .then(function (importerFunc) {
             return importerFunc(data);
-        }, function (reason) {
-            return when.reject(reason);
         });
 };
 
 Importer000.prototype.canImport = function (data) {
     if (data.meta && data.meta.version && this.importFrom[data.meta.version]) {
-        return when.resolve(this.importFrom[data.meta.version]);
+        return Promise.resolve(this.importFrom[data.meta.version]);
     }
 
-    return when.reject('Unsupported version of data: ' + data.meta.version);
+    return Promise.reject('Unsupported version of data: ' + data.meta.version);
 };
 
 
@@ -49,10 +47,10 @@ Importer000.prototype.loadUsers = function () {
         });
 
         if (!users.owner) {
-            return when.reject('Unable to find an owner');
+            return Promise.reject('Unable to find an owner');
         }
 
-        return when.resolve(users);
+        return users;
     });
 };
 
@@ -72,12 +70,12 @@ Importer000.prototype.doUserImport = function (t, tableData, users, errors) {
         // Import users, deduplicating with already present users
         userOps = utils.importUsers(tableData.users, users, t);
 
-        return when.settle(userOps).then(function (descriptors) {
+        return Promise.settle(userOps).then(function (descriptors) {
             descriptors.forEach(function (d) {
-                if (d.state === 'rejected') {
-                    errors = errors.concat(d.reason);
+                if (d.isRejected()) {
+                    errors = errors.concat(d.reason());
                 } else {
-                    imported.push(d.value.toJSON());
+                    imported.push(d.value().toJSON());
                 }
             });
 
@@ -85,12 +83,12 @@ Importer000.prototype.doUserImport = function (t, tableData, users, errors) {
             if (errors.length > 0) {
                 t.rollback(errors);
             } else {
-                return when.resolve(imported);
+                return imported;
             }
         });
     }
 
-    return when.resolve({});
+    return Promise.resolve({});
 };
 
 Importer000.prototype.doImport = function (data) {
@@ -149,13 +147,12 @@ Importer000.prototype.doImport = function (data) {
                  */
 
                 // Write changes to DB, if successful commit, otherwise rollback
-                // when.all() does not work as expected, when.settle() does.
-                when.settle(ops).then(function (descriptors) {
+                Promise.settle(ops).then(function (descriptors) {
                     var errors = [];
 
                     descriptors.forEach(function (d) {
-                        if (d.state === 'rejected') {
-                            errors = errors.concat(d.reason);
+                        if (d.isRejected()) {
+                            errors = errors.concat(d.reason());
                         }
                     });
 
@@ -168,9 +165,7 @@ Importer000.prototype.doImport = function (data) {
             });
         }).then(function () {
             //TODO: could return statistics of imported items
-            return when.resolve();
-        }, function (error) {
-            return when.reject(error);
+            return Promise.resolve();
         });
     });
 };
diff --git a/core/server/data/import/index.js b/core/server/data/import/index.js
index a3be3734ed..a90a74b7df 100644
--- a/core/server/data/import/index.js
+++ b/core/server/data/import/index.js
@@ -1,4 +1,4 @@
-var when            = require('when'),
+var Promise         = require('bluebird'),
     _               = require('lodash'),
     validation      = require('../validation'),
     errors          = require('../../errors'),
@@ -43,7 +43,7 @@ handleErrors = function handleErrors(errorList) {
     var processedErrors = [];
 
     if (!_.isArray(errorList)) {
-        return when.reject(errorList);
+        return Promise.reject(errorList);
     }
 
     _.each(errorList, function (error) {
@@ -57,7 +57,7 @@ handleErrors = function handleErrors(errorList) {
         }
     });
 
-    return when.reject(processedErrors);
+    return Promise.reject(processedErrors);
 };
 
 validate = function validate(data) {
@@ -69,20 +69,18 @@ validate = function validate(data) {
         });
     });
 
-    return when.settle(validateOps).then(function (descriptors) {
+    return Promise.settle(validateOps).then(function (descriptors) {
         var errorList = [];
 
         _.each(descriptors, function (d) {
-            if (d.state === 'rejected') {
-                errorList = errorList.concat(d.reason);
+            if (d.isRejected()) {
+                errorList = errorList.concat(d.reason());
             }
         });
 
         if (!_.isEmpty(errorList)) {
-            return when.reject(errorList);
+            return Promise.reject(errorList);
         }
-
-        return when.resolve();
     });
 };
 
@@ -97,7 +95,7 @@ module.exports = function (version, data) {
         }
 
         if (!importer) {
-            return when.reject('No importer found');
+            return Promise.reject('No importer found');
         }
 
         return importer.importData(data);
diff --git a/core/server/data/import/utils.js b/core/server/data/import/utils.js
index 7607115fd3..2abdbddc6d 100644
--- a/core/server/data/import/utils.js
+++ b/core/server/data/import/utils.js
@@ -1,4 +1,4 @@
-var when        = require('when'),
+var Promise     = require('bluebird'),
     _           = require('lodash'),
     models      = require('../../models'),
     errors      = require('../../errors'),
@@ -162,10 +162,11 @@ utils = {
                     return models.Tag.add(tag, _.extend(internal, {transacting: transaction}))
                         // add pass-through error handling so that bluebird doesn't think we've dropped it
                         .catch(function (error) {
-                            return when.reject({raw: error, model: 'tag', data: tag});
+                            return Promise.reject({raw: error, model: 'tag', data: tag});
                         });
                 }
-                return when.resolve(_tag);
+
+                return _tag;
             }));
         });
     },
@@ -180,7 +181,7 @@ utils = {
             ops.push(models.Post.add(post, _.extend(internal, {transacting: transaction, importing: true}))
                 // add pass-through error handling so that bluebird doesn't think we've dropped it
                 .catch(function (error) {
-                    return when.reject({raw: error, model: 'post', data: post});
+                    return Promise.reject({raw: error, model: 'post', data: post});
                 }));
         });
     },
@@ -207,7 +208,7 @@ utils = {
             ops.push(models.User.add(user, _.extend(internal, {transacting: transaction}))
                 // add pass-through error handling so that bluebird doesn't think we've dropped it
                 .catch(function (error) {
-                    return when.reject({raw: error, model: 'user', data: user});
+                    return Promise.reject({raw: error, model: 'user', data: user});
                 }));
         });
 
@@ -233,7 +234,7 @@ utils = {
         ops.push(models.Settings.edit(tableData, _.extend(internal, {transacting: transaction}))
              // add pass-through error handling so that bluebird doesn't think we've dropped it
              .catch(function (error) {
-                return when.reject({raw: error, model: 'setting', data: tableData});
+                return Promise.reject({raw: error, model: 'setting', data: tableData});
             }));
     },
 
@@ -247,13 +248,14 @@ utils = {
                     return models.App.add(app, _.extend(internal, {transacting: transaction}))
                         // add pass-through error handling so that bluebird doesn't think we've dropped it
                         .catch(function (error) {
-                            return when.reject({raw: error, model: 'app', data: app});
+                            return Promise.reject({raw: error, model: 'app', data: app});
                         });
                 }
-                return when.resolve(_app);
+
+                return _app;
             }));
         });
     }
 };
 
-module.exports = utils;
\ No newline at end of file
+module.exports = utils;
diff --git a/core/server/data/migration/index.js b/core/server/data/migration/index.js
index c8f3f871b5..11bc2a4f79 100644
--- a/core/server/data/migration/index.js
+++ b/core/server/data/migration/index.js
@@ -1,11 +1,9 @@
 var _               = require('lodash'),
-    when            = require('when'),
+    Promise         = require('bluebird'),
+    sequence        = require('../../utils/sequence'),
     path            = require('path'),
     fs              = require('fs'),
-    nodefn          = require('when/node'),
     errors          = require('../../errors'),
-    sequence        = require('when/sequence'),
-
     commands        = require('./commands'),
     versioning      = require('../versioning'),
     models          = require('../../models'),
@@ -47,7 +45,7 @@ backupDatabase = function backupDatabase() {
         return dataExport.fileName().then(function (fileName) {
             fileName = path.resolve(config.paths.contentPath + '/data/' + fileName);
 
-            return nodefn.call(fs.writeFile, fileName, JSON.stringify(exportedData)).then(function () {
+            return Promise.promisify(fs.writeFile)(fileName, JSON.stringify(exportedData)).then(function () {
                 logInfo('Database backup written to: ' + fileName);
             });
         });
@@ -80,7 +78,7 @@ init = function (tablesOnly) {
         if (databaseVersion === defaultVersion) {
             // 1. The database exists and is up-to-date
             logInfo('Up to date at version ' + databaseVersion);
-            return when.resolve();
+            return;
         }
 
         if (databaseVersion > defaultVersion) {
@@ -155,7 +153,7 @@ migrateUp = function (fromVersion, toVersion) {
     }).then(function () {
         migrateOps = migrateOps.concat(commands.getDeleteCommands(oldTables, schemaTables));
         migrateOps = migrateOps.concat(commands.getAddCommands(oldTables, schemaTables));
-        return when.all(
+        return Promise.all(
             _.map(oldTables, function (table) {
                 return utils.getIndexes(table).then(function (indexes) {
                     modifyUniCommands = modifyUniCommands.concat(commands.modifyUniqueCommands(table, indexes));
@@ -163,7 +161,7 @@ migrateUp = function (fromVersion, toVersion) {
             })
         );
     }).then(function () {
-        return when.all(
+        return Promise.all(
             _.map(oldTables, function (table) {
                 return utils.getColumns(table).then(function (columns) {
                     migrateOps = migrateOps.concat(commands.addColumnCommands(table, columns));
@@ -177,9 +175,9 @@ migrateUp = function (fromVersion, toVersion) {
         // execute the commands in sequence
         if (!_.isEmpty(migrateOps)) {
             logInfo('Running migrations');
+
             return sequence(migrateOps);
         }
-        return;
     }).then(function () {
         return fixtures.update(fromVersion, toVersion);
     }).then(function () {
@@ -192,4 +190,4 @@ module.exports = {
     reset: reset,
     migrateUp: migrateUp,
     migrateUpFreshDb: migrateUpFreshDb
-};
\ No newline at end of file
+};
diff --git a/core/server/data/utils/clients/mysql.js b/core/server/data/utils/clients/mysql.js
index c882b0c2d7..4076bd3c7c 100644
--- a/core/server/data/utils/clients/mysql.js
+++ b/core/server/data/utils/clients/mysql.js
@@ -1,5 +1,4 @@
 var _       = require('lodash'),
-    when    = require('when'),
     config  = require('../../../config/index'),
 
     //private
@@ -43,9 +42,7 @@ checkPostTable = function checkPostTable() {
     return config.database.knex.raw('SHOW FIELDS FROM posts where Field ="html" OR Field = "markdown"').then(function (response) {
         return _.flatten(_.map(response[0], function (entry) {
             if (entry.Type.toLowerCase() !== 'mediumtext') {
-                return config.database.knex.raw('ALTER TABLE posts MODIFY ' + entry.Field + ' MEDIUMTEXT').then(function () {
-                    return when.resolve();
-                });
+                return config.database.knex.raw('ALTER TABLE posts MODIFY ' + entry.Field + ' MEDIUMTEXT');
             }
         }));
     });
@@ -56,4 +53,4 @@ module.exports = {
     getTables:  getTables,
     getIndexes: getIndexes,
     getColumns: getColumns
-};
\ No newline at end of file
+};
diff --git a/core/server/data/utils/clients/sqlite3.js b/core/server/data/utils/clients/sqlite3.js
index b0a12ff773..a24738ddcb 100644
--- a/core/server/data/utils/clients/sqlite3.js
+++ b/core/server/data/utils/clients/sqlite3.js
@@ -1,13 +1,13 @@
 var _       = require('lodash'),
     config  = require('../../../config/index'),
 
-        //private
-        doRaw,
+    //private
+    doRaw,
 
-        // public
-        getTables,
-        getIndexes,
-        getColumns;
+    // public
+    getTables,
+    getIndexes,
+    getColumns;
 
 
 doRaw = function doRaw(query, fn) {
diff --git a/core/server/data/utils/index.js b/core/server/data/utils/index.js
index 64c2a0d99f..48ae15871c 100644
--- a/core/server/data/utils/index.js
+++ b/core/server/data/utils/index.js
@@ -1,5 +1,5 @@
 var _       = require('lodash'),
-    when    = require('when'),
+    Promise = require('bluebird'),
     config  = require('../../config'),
     schema  = require('../schema').tables,
     clients = require('./clients'),
@@ -87,7 +87,7 @@ function getTables() {
         return clients[client].getTables();
     }
 
-    return when.reject('No support for database client ' + client);
+    return Promise.reject('No support for database client ' + client);
 }
 
 function getIndexes(table) {
@@ -98,7 +98,7 @@ function getIndexes(table) {
         return clients[client].getIndexes(table);
     }
 
-    return when.reject('No support for database client ' + client);
+    return Promise.reject('No support for database client ' + client);
 }
 
 function getColumns(table) {
@@ -109,7 +109,7 @@ function getColumns(table) {
         return clients[client].getColumns(table);
     }
 
-    return when.reject('No support for database client ' + client);
+    return Promise.reject('No support for database client ' + client);
 }
 
 function checkTables() {
diff --git a/core/server/data/validation/index.js b/core/server/data/validation/index.js
index e4ab57f9f8..90e72eb8b2 100644
--- a/core/server/data/validation/index.js
+++ b/core/server/data/validation/index.js
@@ -1,7 +1,7 @@
 var schema    = require('../schema').tables,
     _         = require('lodash'),
     validator = require('validator'),
-    when      = require('when'),
+    Promise   = require('bluebird'),
     errors    = require('../../errors'),
     config    = require('../../config'),
     requireTree = require('../../require-tree').readAll,
@@ -73,10 +73,10 @@ validateSchema = function (tableName, model) {
     });
 
     if (validationErrors.length !== 0) {
-        return when.reject(validationErrors);
+        return Promise.reject(validationErrors);
     }
 
-    return when.resolve();
+    return Promise.resolve();
 };
 
 // Validation for settings
@@ -92,10 +92,10 @@ validateSettings = function (defaultSettings, model) {
     }
 
     if (validationErrors.length !== 0) {
-        return when.reject(validationErrors);
+        return Promise.reject(validationErrors);
     }
 
-    return when.resolve();
+    return Promise.resolve();
 };
 
 // A Promise that will resolve to an object with a property for each installed theme.
@@ -107,15 +107,13 @@ validateActiveTheme = function (themeName) {
     // If Ghost is running and its availableThemes collection exists
     // give it priority.
     if (config.paths.availableThemes && Object.keys(config.paths.availableThemes).length > 0) {
-        availableThemes = when(config.paths.availableThemes);
+        availableThemes = Promise.resolve(config.paths.availableThemes);
     }
 
     return availableThemes.then(function (themes) {
         if (!themes.hasOwnProperty(themeName)) {
-            return when.reject(new errors.ValidationError(themeName + ' cannot be activated because it is not currently installed.', 'activeTheme'));
+            return Promise.reject(new errors.ValidationError(themeName + ' cannot be activated because it is not currently installed.', 'activeTheme'));
         }
-
-        return when.resolve();
     });
 };
 
diff --git a/core/server/errors/index.js b/core/server/errors/index.js
index 60ffa9ddf5..4f807c5cc5 100644
--- a/core/server/errors/index.js
+++ b/core/server/errors/index.js
@@ -3,7 +3,7 @@ var _                          = require('lodash'),
     colors                     = require('colors'),
     config                     = require('../config'),
     path                       = require('path'),
-    when                       = require('when'),
+    Promise                    = require('bluebird'),
     hbs                        = require('express-hbs'),
     NotFoundError              = require('./notfounderror'),
     BadRequestError            = require('./badrequesterror'),
@@ -47,7 +47,7 @@ errors = {
     // ## Reject Error
     // Used to pass through promise errors when we want to handle them at a later time
     rejectError: function (err) {
-        return when.reject(err);
+        return Promise.reject(err);
     },
 
     logInfo: function (component, info) {
diff --git a/core/server/filters.js b/core/server/filters.js
index b4601603b7..ac91fc18d0 100644
--- a/core/server/filters.js
+++ b/core/server/filters.js
@@ -1,10 +1,8 @@
-var when          = require('when'),
+var Promise       = require('bluebird'),
+    pipeline      = require('./utils/pipeline'),
     _             = require('lodash'),
-
     defaults;
 
-when.pipeline = require('when/pipeline');
-
 // ## Default values
 /**
  * A hash of default values to use instead of 'magic' numbers/strings.
@@ -64,7 +62,7 @@ Filters.prototype.doFilter = function (name, args, context) {
 
     // Bug out early if no callbacks by that name
     if (!callbacks) {
-        return when.resolve(args);
+        return Promise.resolve(args);
     }
 
     // For each priorityLevel
@@ -75,7 +73,7 @@ Filters.prototype.doFilter = function (name, args, context) {
 
             // Bug out if no handlers on this priority
             if (!_.isArray(callbacks[priority])) {
-                return when.resolve(currentArgs);
+                return Promise.resolve(currentArgs);
             }
 
             callables = _.map(callbacks[priority], function (callback) {
@@ -84,11 +82,11 @@ Filters.prototype.doFilter = function (name, args, context) {
                 };
             });
             // Call each handler for this priority level, allowing for promises or values
-            return when.pipeline(callables, currentArgs);
+            return pipeline(callables, currentArgs);
         });
     });
 
-    return when.pipeline(priorityCallbacks, args);
+    return pipeline(priorityCallbacks, args);
 };
 
 module.exports = new Filters();
diff --git a/core/server/helpers/index.js b/core/server/helpers/index.js
index b7294b17e3..727efee2b2 100644
--- a/core/server/helpers/index.js
+++ b/core/server/helpers/index.js
@@ -2,8 +2,7 @@ var downsize        = require('downsize'),
     hbs             = require('express-hbs'),
     moment          = require('moment'),
     _               = require('lodash'),
-    when            = require('when'),
-
+    Promise         = require('bluebird'),
     api             = require('../api'),
     config          = require('../config'),
     errors          = require('../errors'),
@@ -147,15 +146,15 @@ coreHelpers.url = function (options) {
     }
 
     if (schema.isTag(this)) {
-        return when(config.urlFor('tag', {tag: this}, absolute));
+        return Promise.resolve(config.urlFor('tag', {tag: this}, absolute));
     }
 
     if (schema.isUser(this)) {
-        return when(config.urlFor('author', {author: this}, absolute));
+        return Promise.resolve(config.urlFor('author', {author: this}, absolute));
     }
 
 
-    return when(config.urlFor(this, absolute));
+    return Promise.resolve(config.urlFor(this, absolute));
 };
 
 // ### Asset helper
@@ -786,9 +785,9 @@ function registerAsyncHelper(hbs, name, fn) {
     hbs.registerAsyncHelper(name, function (options, cb) {
         // Wrap the function passed in with a when.resolve so it can
         // return either a promise or a value
-        when.resolve(fn.call(this, options)).then(function (result) {
+        Promise.resolve(fn.call(this, options)).then(function (result) {
             cb(result);
-        }).otherwise(function (err) {
+        }).catch(function (err) {
             errors.logAndThrowError(err, 'registerAsyncThemeHelper: ' + name);
         });
     });
diff --git a/core/server/index.js b/core/server/index.js
index 86832df547..c2da0d66b4 100644
--- a/core/server/index.js
+++ b/core/server/index.js
@@ -6,7 +6,7 @@ var crypto      = require('crypto'),
     fs          = require('fs'),
     uuid        = require('node-uuid'),
     _           = require('lodash'),
-    when        = require('when'),
+    Promise     = require('bluebird'),
 
     api         = require('./api'),
     config      = require('./config'),
@@ -24,13 +24,6 @@ var crypto      = require('crypto'),
 // Variables
     dbHash;
 
-// If we're in development mode, require "when/console/monitor"
-// for help in seeing swallowed promise errors, and log any
-// stderr messages from bluebird promises.
-if (process.env.NODE_ENV === 'development') {
-    require('when/monitor/console');
-}
-
 function doFirstRun() {
     var firstRunMessage = [
         'Welcome to Ghost.',
@@ -80,30 +73,29 @@ function builtFilesExist() {
             helpers.scriptFiles.production : helpers.scriptFiles.development;
 
     function checkExist(fileName) {
-        var deferred = when.defer(),
-            errorMessage = "Javascript files have not been built.",
+        var errorMessage = "Javascript files have not been built.",
             errorHelp = "\nPlease read the getting started instructions at:" +
                         "\nhttps://github.com/TryGhost/Ghost#getting-started-guide-for-developers";
 
-        fs.exists(fileName, function (exists) {
-            if (exists) {
-                deferred.resolve(true);
-            } else {
-                var err = new Error(errorMessage);
+        return new Promise(function (resolve, reject) {
+            fs.exists(fileName, function (exists) {
+                if (exists) {
+                    resolve(true);
+                } else {
+                    var err = new Error(errorMessage);
 
-                err.help = errorHelp;
-                deferred.reject(err);
-            }
+                    err.help = errorHelp;
+                    reject(err);
+                }
+            });
         });
-
-        return deferred.promise;
     }
 
     fileNames.forEach(function (fileName) {
         deferreds.push(checkExist(location + fileName));
     });
 
-    return when.all(deferreds);
+    return Promise.all(deferreds);
 }
 
 // This is run after every initialization is done, right before starting server.
@@ -174,7 +166,7 @@ function init(server) {
         // into this method due to circular dependencies.
         return config.theme.update(api.settings, config.url);
     }).then(function () {
-        return when.join(
+        return Promise.join(
             // Check for or initialise a dbHash.
             initDbHashAndFirstRun(),
             // Initialize mail
@@ -219,7 +211,6 @@ function init(server) {
             errors.logWarn(warn.message, warn.context, warn.help);
         });
 
-
         return new GhostServer(server);
     });
 }
diff --git a/core/server/mail.js b/core/server/mail.js
index 0c76217ef5..26a9d9e28b 100644
--- a/core/server/mail.js
+++ b/core/server/mail.js
@@ -1,7 +1,6 @@
 var cp         = require('child_process'),
     _          = require('lodash'),
-    when       = require('when'),
-    nodefn     = require('when/node'),
+    Promise    = require('bluebird'),
     nodemailer = require('nodemailer'),
     config     = require('./config');
 
@@ -17,7 +16,7 @@ GhostMailer.prototype.init = function () {
     self.state = {};
     if (config.mail && config.mail.transport) {
         this.createTransport();
-        return when.resolve();
+        return Promise.resolve();
     }
 
     // Attempt to detect and fallback to `sendmail`
@@ -26,11 +25,9 @@ GhostMailer.prototype.init = function () {
             path: binpath
         });
         self.state.usingSendmail = true;
-    }, function () {
+    }).catch(function () {
         self.state.emailDisabled = true;
         self.transport = null;
-    }).ensure(function () {
-        return when.resolve();
     });
 };
 
@@ -40,13 +37,15 @@ GhostMailer.prototype.isWindows = function () {
 
 GhostMailer.prototype.detectSendmail = function () {
     if (this.isWindows()) {
-        return when.reject();
+        return Promise.reject();
     }
-    return when.promise(function (resolve, reject) {
+
+    return new Promise(function (resolve, reject) {
         cp.exec('which sendmail', function (err, stdout) {
             if (err && !/bin\/sendmail/.test(stdout)) {
                 return reject();
             }
+
             resolve(stdout.toString().replace(/(\n|\r|\r\n)$/, ''));
         });
     });
@@ -63,7 +62,7 @@ GhostMailer.prototype.fromAddress = function () {
 
     if (!from) {
         // Extract the domain name from url set in config.js
-        domain = config.url.match(new RegExp("^https?://([^/:?#]+)(?:[/:?#]|$)", "i"));
+        domain = config.url.match(new RegExp('^https?://([^/:?#]+)(?:[/:?#]|$)', 'i'));
         domain = domain && domain[1];
 
         // Default to ghost@[blog.url]
@@ -84,12 +83,12 @@ GhostMailer.prototype.send = function (message) {
     to = message.to || false;
 
     if (!this.transport) {
-        return when.reject(new Error('Email Error: No e-mail transport configured.'));
+        return Promise.reject(new Error('Email Error: No e-mail transport configured.'));
     }
     if (!(message && message.subject && message.html && message.to)) {
-        return when.reject(new Error('Email Error: Incomplete message data.'));
+        return Promise.reject(new Error('Email Error: Incomplete message data.'));
     }
-    sendMail = nodefn.lift(self.transport.sendMail.bind(self.transport));
+    sendMail = Promise.promisify(self.transport.sendMail.bind(self.transport));
 
     message = _.extend(message, {
         from: self.fromAddress(),
diff --git a/core/server/middleware/index.js b/core/server/middleware/index.js
index ce0e110c3a..76af9b0693 100644
--- a/core/server/middleware/index.js
+++ b/core/server/middleware/index.js
@@ -130,7 +130,7 @@ function updateActiveTheme(req, res, next) {
             }
         }
         next();
-    }).otherwise(function (err) {
+    }).catch(function (err) {
         // Trying to start up without the active theme present, setup a simple hbs instance
         // and render an error page straight away.
         expressServer.engine('hbs', hbs.express3());
@@ -147,7 +147,7 @@ function redirectToSetup(req, res, next) {
             return res.redirect(config.paths.subdir + '/ghost/setup/');
         }
         next();
-    }).otherwise(function (err) {
+    }).catch(function (err) {
         return next(new Error(err));
     });
 }
diff --git a/core/server/models/base.js b/core/server/models/base.js
index 2670252c17..2a4c796aaa 100644
--- a/core/server/models/base.js
+++ b/core/server/models/base.js
@@ -6,7 +6,7 @@
 // accesses the models directly. All other parts of Ghost, including the blog frontend, admin UI, and apps are only
 // allowed to access data via the API.
 var bookshelf  = require('bookshelf'),
-    when       = require('when'),
+    Promise    = require('bluebird'),
     moment     = require('moment'),
     _          = require('lodash'),
     uuid       = require('node-uuid'),
@@ -55,7 +55,7 @@ ghostBookshelf.Model = ghostBookshelf.Model.extend({
 
         this.on('creating', this.creating, this);
         this.on('saving', function (model, attributes, options) {
-            return when(self.saving(model, attributes, options)).then(function () {
+            return Promise.resolve(self.saving(model, attributes, options)).then(function () {
                 return self.validate(model, attributes, options);
             });
         });
@@ -327,7 +327,7 @@ ghostBookshelf.Model = ghostBookshelf.Model.extend({
                 var trimSpace;
 
                 if (!found) {
-                    return when.resolve(slugToFind);
+                    return slugToFind;
                 }
 
                 slugTryCount += 1;
diff --git a/core/server/models/index.js b/core/server/models/index.js
index 8242010e60..dcd1bf6006 100644
--- a/core/server/models/index.js
+++ b/core/server/models/index.js
@@ -1,5 +1,5 @@
-var _             = require('lodash'),
-    when          = require('when'),
+var _       = require('lodash'),
+    Promise = require('bluebird'),
     requireTree   = require('../require-tree'),
     models;
 
@@ -48,12 +48,12 @@ models = {
         var self = this;
 
         return self.Post.findAll().then(function (posts) {
-            return when.all(_.map(posts.toJSON(), function (post) {
+            return Promise.all(_.map(posts.toJSON(), function (post) {
                 return self.Post.destroy({id: post.id});
             }));
         }).then(function () {
             return self.Tag.findAll().then(function (tags) {
-                return when.all(_.map(tags.toJSON(), function (tag) {
+                return Promise.all(_.map(tags.toJSON(), function (tag) {
                     return self.Tag.destroy({id: tag.id});
                 }));
             });
diff --git a/core/server/models/post.js b/core/server/models/post.js
index 0e74c19bf2..03838f2270 100644
--- a/core/server/models/post.js
+++ b/core/server/models/post.js
@@ -1,7 +1,7 @@
 // # Post Model
 var _              = require('lodash'),
     uuid           = require('node-uuid'),
-    when           = require('when'),
+    Promise        = require('bluebird'),
     errors         = require('../errors'),
     Showdown       = require('showdown'),
     ghostgfm       = require('../../shared/lib/showdown/extensions/ghostgfm'),
@@ -123,7 +123,7 @@ Post = ghostBookshelf.Model.extend({
             tagOps.push(post.tags().detach(null, _.omit(options, 'query')));
 
             if (_.isEmpty(self.myTags)) {
-                return when.all(tagOps);
+                return Promise.all(tagOps);
             }
 
             return ghostBookshelf.collection('Tags').forge().query('whereIn', 'name', _.pluck(self.myTags, 'name')).fetch(options).then(function (existingTags) {
@@ -157,7 +157,7 @@ Post = ghostBookshelf.Model.extend({
                     tagOps.push(post.tags().attach(tag.id, _.omit(options, 'query')));
                 });
 
-                return when.all(tagOps);
+                return Promise.all(tagOps);
             });
         });
     },
@@ -341,7 +341,7 @@ Post = ghostBookshelf.Model.extend({
             return false;
         }
 
-        return when.join(fetchTagQuery(), fetchAuthorQuery())
+        return Promise.join(fetchTagQuery(), fetchAuthorQuery())
 
             // Set the limit & offset for the query, fetching
             // with the opts (to specify any eager relations, etc.)
@@ -536,16 +536,16 @@ Post = ghostBookshelf.Model.extend({
         options = this.filterOptions(options, 'destroyByAuthor');
         if (authorId) {
             return postCollection.query('where', 'author_id', '=', authorId).fetch(options).then(function (results) {
-                return when.map(results.models, function (post) {
+                return Promise.map(results.models, function (post) {
                     return post.related('tags').detach(null, options).then(function () {
                         return post.destroy(options);
                     });
                 });
             }, function (error) {
-                return when.reject(new errors.InternalServerError(error.message || error));
+                return Promise.reject(new errors.InternalServerError(error.message || error));
             });
         }
-        return when.reject(new errors.NotFoundError('No user found'));
+        return Promise.reject(new errors.NotFoundError('No user found'));
     },
 
 
@@ -574,10 +574,10 @@ Post = ghostBookshelf.Model.extend({
         }
 
         if (hasUserPermission && hasAppPermission) {
-            return when.resolve();
+            return Promise.resolve();
         }
 
-        return when.reject();
+        return Promise.reject();
     }
 });
 
diff --git a/core/server/models/role.js b/core/server/models/role.js
index 0981ebbedd..d1b5a96335 100644
--- a/core/server/models/role.js
+++ b/core/server/models/role.js
@@ -1,7 +1,7 @@
 var _              = require('lodash'),
     errors         = require('../errors'),
     ghostBookshelf = require('./base'),
-    when           = require('when'),
+    Promise        = require('bluebird'),
 
     Role,
     Roles;
@@ -73,9 +73,10 @@ Role = ghostBookshelf.Model.extend({
         }
 
         if (hasUserPermission && hasAppPermission) {
-            return when.resolve();
+            return Promise.resolve();
         }
-        return when.reject();
+
+        return Promise.reject();
     }
 });
 
diff --git a/core/server/models/settings.js b/core/server/models/settings.js
index 4033140fb9..4555f9959d 100644
--- a/core/server/models/settings.js
+++ b/core/server/models/settings.js
@@ -3,7 +3,7 @@ var Settings,
     uuid           = require('node-uuid'),
     _              = require('lodash'),
     errors         = require('../errors'),
-    when           = require('when'),
+    Promise        = require('bluebird'),
     validation     = require('../data/validation'),
     internal       = {context: {internal: true}},
 
@@ -64,7 +64,7 @@ Settings = ghostBookshelf.Model.extend({
             var themeName = setting.value || '';
 
             if (setting.key !== 'activeTheme') {
-                return when.resolve();
+                return;
             }
 
             return validation.validateActiveTheme(themeName);
@@ -87,7 +87,7 @@ Settings = ghostBookshelf.Model.extend({
         if (!_.isObject(options)) {
             options = { key: options };
         }
-        return when(ghostBookshelf.Model.findOne.call(this, options));
+        return Promise.resolve(ghostBookshelf.Model.findOne.call(this, options));
     },
 
     edit: function (data, options) {
@@ -98,11 +98,11 @@ Settings = ghostBookshelf.Model.extend({
             data = [data];
         }
 
-        return when.map(data, function (item) {
+        return Promise.map(data, function (item) {
             // Accept an array of models as input
             if (item.toJSON) { item = item.toJSON(); }
             if (!(_.isString(item.key) && item.key.length > 0)) {
-                return when.reject(new errors.ValidationError('Value in [settings.key] cannot be blank.'));
+                return Promise.reject(new errors.ValidationError('Value in [settings.key] cannot be blank.'));
             }
 
             item = self.filterData(item);
@@ -113,7 +113,7 @@ Settings = ghostBookshelf.Model.extend({
                     return setting.save({value: item.value}, options);
                 }
 
-                return when.reject(new errors.NotFoundError('Unable to find setting to update: ' + item.key));
+                return Promise.reject(new errors.NotFoundError('Unable to find setting to update: ' + item.key));
 
             }, errors.logAndThrowError);
         });
@@ -121,7 +121,7 @@ Settings = ghostBookshelf.Model.extend({
 
     populateDefault: function (key) {
         if (!getDefaultSettings()[key]) {
-            return when.reject(new errors.NotFoundError('Unable to find default setting: ' + key));
+            return Promise.reject(new errors.NotFoundError('Unable to find default setting: ' + key));
         }
 
         return this.findOne({ key: key }).then(function (foundSetting) {
@@ -153,7 +153,7 @@ Settings = ghostBookshelf.Model.extend({
                 }
             });
 
-            return when.all(insertOperations);
+            return Promise.all(insertOperations);
         });
     }
 
diff --git a/core/server/models/user.js b/core/server/models/user.js
index c7aa37e0f6..8ca9652547 100644
--- a/core/server/models/user.js
+++ b/core/server/models/user.js
@@ -1,7 +1,6 @@
 var _              = require('lodash'),
-    when           = require('when'),
+    Promise        = require('bluebird'),
     errors         = require('../errors'),
-    nodefn         = require('when/node'),
     bcrypt         = require('bcryptjs'),
     ghostBookshelf = require('./base'),
     http           = require('http'),
@@ -9,6 +8,10 @@ var _              = require('lodash'),
     validator      = require('validator'),
     validation     = require('../data/validation'),
 
+    bcryptGenSalt  = Promise.promisify(bcrypt.genSalt),
+    bcryptHash     = Promise.promisify(bcrypt.hash),
+    bcryptCompare  = Promise.promisify(bcrypt.compare),
+
     tokenSecurity  = {},
     activeStates   = ['active', 'warn-1', 'warn-2', 'warn-3', 'warn-4', 'locked'],
     invitedStates  = ['invited', 'invited-pending'],
@@ -21,16 +24,16 @@ function validatePasswordLength(password) {
             throw new Error('Your password must be at least 8 characters long.');
         }
     } catch (error) {
-        return when.reject(error);
+        return Promise.reject(error);
     }
-    return when.resolve();
+    return Promise.resolve();
 }
 
 function generatePasswordHash(password) {
     // Generate a new salt
-    return nodefn.call(bcrypt.genSalt).then(function (salt) {
+    return bcryptGenSalt().then(function (salt) {
         // Hash the provided password with bcrypt
-        return nodefn.call(bcrypt.hash, password, salt);
+        return bcryptHash(password, salt);
     });
 }
 
@@ -239,7 +242,7 @@ User = ghostBookshelf.Model.extend({
             return false;
         }
 
-        return when(fetchRoleQuery())
+        return Promise.resolve(fetchRoleQuery())
             .then(function () {
 
                 if (roleInstance) {
@@ -394,7 +397,7 @@ User = ghostBookshelf.Model.extend({
                 roleId = parseInt(data.roles[0].id || data.roles[0], 10);
 
                 if (data.roles.length > 1) {
-                    return when.reject(
+                    return Promise.reject(
                         new errors.ValidationError('Only one role per user is supported at the moment.')
                     );
                 }
@@ -407,7 +410,7 @@ User = ghostBookshelf.Model.extend({
                     return ghostBookshelf.model('Role').findOne({id: roleId});
                 }).then(function (roleToAssign) {
                     if (roleToAssign && roleToAssign.get('name') === 'Owner') {
-                        return when.reject(
+                        return Promise.reject(
                             new errors.ValidationError('This method does not support assigning the owner role')
                         );
                     } else {
@@ -447,7 +450,7 @@ User = ghostBookshelf.Model.extend({
 
             // check for too many roles
             if (roles.length > 1) {
-                return when.reject(new errors.ValidationError('Only one role per user is supported at the moment.'));
+                return Promise.reject(new errors.ValidationError('Only one role per user is supported at the moment.'));
             }
             // remove roles from the object
             delete data.roles;
@@ -552,7 +555,7 @@ User = ghostBookshelf.Model.extend({
         if (action === 'destroy') {
             // Owner cannot be deleted EVER
             if (userModel.hasRole('Owner')) {
-                return when.reject();
+                return Promise.reject();
             }
 
             // Users with the role 'Editor' have complex permissions when the action === 'destroy'
@@ -566,10 +569,10 @@ User = ghostBookshelf.Model.extend({
         }
 
         if (hasUserPermission && hasAppPermission) {
-            return when.resolve();
+            return Promise.resolve();
         }
 
-        return when.reject();
+        return Promise.reject();
     },
 
     setWarning: function (user, options) {
@@ -588,7 +591,7 @@ User = ghostBookshelf.Model.extend({
                 user.set('status', 'warn-' + level);
             }
         }
-        return when(user.save(options)).then(function () {
+        return Promise.resolve(user.save(options)).then(function () {
             return 5 - level;
         });
     },
@@ -599,19 +602,19 @@ User = ghostBookshelf.Model.extend({
             s;
         return this.getByEmail(object.email).then(function (user) {
             if (!user) {
-                return when.reject(new errors.NotFoundError('There is no user with that email address.'));
+                return Promise.reject(new errors.NotFoundError('There is no user with that email address.'));
             }
             if (user.get('status') === 'invited' || user.get('status') === 'invited-pending' ||
                     user.get('status') === 'inactive'
                 ) {
-                return when.reject(new Error('The user with that email address is inactive.'));
+                return Promise.reject(new Error('The user with that email address is inactive.'));
             }
             if (user.get('status') !== 'locked') {
-                return nodefn.call(bcrypt.compare, object.password, user.get('password')).then(function (matched) {
+                return bcryptCompare(object.password, user.get('password')).then(function (matched) {
                     if (!matched) {
-                        return when(self.setWarning(user, {validate: false})).then(function (remaining) {
+                        return Promise.resolve(self.setWarning(user, {validate: false})).then(function (remaining) {
                             s = (remaining > 1) ? 's' : '';
-                            return when.reject(new errors.UnauthorizedError('Your password is incorrect.<br>' +
+                            return Promise.reject(new errors.UnauthorizedError('Your password is incorrect.<br>' +
                                 remaining + ' attempt' + s + ' remaining!'));
 
                             // Use comma structure, not .catch, because we don't want to catch incorrect passwords
@@ -624,11 +627,11 @@ User = ghostBookshelf.Model.extend({
                                 'Error thrown from user update during login',
                                 'Visit and save your profile after logging in to check for problems.'
                             );
-                            return when.reject(new errors.UnauthorizedError('Your password is incorrect.'));
+                            return Promise.reject(new errors.UnauthorizedError('Your password is incorrect.'));
                         });
                     }
 
-                    return when(user.set({status : 'active', last_login : new Date()}).save({validate: false}))
+                    return Promise.resolve(user.set({status : 'active', last_login : new Date()}).save({validate: false}))
                         .catch(function (error) {
                             // If we get a validation or other error during this save, catch it and log it, but don't
                             // cause a login error because of it. The user validation is not important here.
@@ -641,16 +644,16 @@ User = ghostBookshelf.Model.extend({
                         });
                 }, errors.logAndThrowError);
             }
-            return when.reject(new errors.NoPermissionError('Your account is locked due to too many ' +
+            return Promise.reject(new errors.NoPermissionError('Your account is locked due to too many ' +
                 'login attempts. Please reset your password to log in again by clicking ' +
                 'the "Forgotten password?" link!'));
 
         }, function (error) {
             if (error.message === 'NotFound' || error.message === 'EmptyResponse') {
-                return when.reject(new errors.NotFoundError('There is no user with that email address.'));
+                return Promise.reject(new errors.NotFoundError('There is no user with that email address.'));
             }
 
-            return when.reject(error);
+            return Promise.reject(error);
         });
     },
 
@@ -664,21 +667,21 @@ User = ghostBookshelf.Model.extend({
             user = null;
 
         if (newPassword !== ne2Password) {
-            return when.reject(new Error('Your new passwords do not match'));
+            return Promise.reject(new Error('Your new passwords do not match'));
         }
 
         return validatePasswordLength(newPassword).then(function () {
             return self.forge({id: userid}).fetch({require: true});
         }).then(function (_user) {
             user = _user;
-            return nodefn.call(bcrypt.compare, oldPassword, user.get('password'));
+            return bcryptCompare(oldPassword, user.get('password'));
         }).then(function (matched) {
             if (!matched) {
-                return when.reject(new Error('Your password is incorrect'));
+                return Promise.reject(new Error('Your password is incorrect'));
             }
-            return nodefn.call(bcrypt.genSalt);
+            return bcryptGenSalt();
         }).then(function (salt) {
-            return nodefn.call(bcrypt.hash, newPassword, salt);
+            return bcryptHash(newPassword, salt);
         }).then(function (hash) {
             user.save({password: hash});
             return user;
@@ -688,7 +691,7 @@ User = ghostBookshelf.Model.extend({
     generateResetToken: function (email, expires, dbHash) {
         return this.getByEmail(email).then(function (foundUser) {
             if (!foundUser) {
-                return when.reject(new errors.NotFoundError('There is no user with that email address.'));
+                return Promise.reject(new errors.NotFoundError('There is no user with that email address.'));
             }
 
             var hash = crypto.createHash('sha256'),
@@ -720,25 +723,25 @@ User = ghostBookshelf.Model.extend({
 
         // Check if invalid structure
         if (!parts || parts.length !== 3) {
-            return when.reject(new Error('Invalid token structure'));
+            return Promise.reject(new Error('Invalid token structure'));
         }
 
         expires = parseInt(parts[0], 10);
         email = parts[1];
 
         if (isNaN(expires)) {
-            return when.reject(new Error('Invalid token expiration'));
+            return Promise.reject(new Error('Invalid token expiration'));
         }
 
         // Check if token is expired to prevent replay attacks
         if (expires < Date.now()) {
-            return when.reject(new Error('Expired token'));
+            return Promise.reject(new Error('Expired token'));
         }
 
         // to prevent brute force attempts to reset the password the combination of email+expires is only allowed for
         // 10 attempts
         if (tokenSecurity[email + '+' + expires] && tokenSecurity[email + '+' + expires].count >= 10) {
-            return when.reject(new Error('Token locked'));
+            return Promise.reject(new Error('Token locked'));
         }
 
         return this.generateResetToken(email, expires, dbHash).then(function (generatedToken) {
@@ -756,14 +759,14 @@ User = ghostBookshelf.Model.extend({
             }
 
             if (diff === 0) {
-                return when.resolve(email);
+                return email;
             }
 
             // increase the count for email+expires for each failed attempt
             tokenSecurity[email + '+' + expires] = {
                 count: tokenSecurity[email + '+' + expires] ? tokenSecurity[email + '+' + expires].count + 1 : 1
             };
-            return when.reject(new Error('Invalid token'));
+            return Promise.reject(new Error('Invalid token'));
         });
     },
 
@@ -771,7 +774,7 @@ User = ghostBookshelf.Model.extend({
         var self = this;
 
         if (newPassword !== ne2Password) {
-            return when.reject(new Error('Your new passwords do not match'));
+            return Promise.reject(new Error('Your new passwords do not match'));
         }
 
         return validatePasswordLength(newPassword).then(function () {
@@ -779,7 +782,7 @@ User = ghostBookshelf.Model.extend({
             return self.validateToken(token, dbHash);
         }).then(function (email) {
             // Fetch the user by email, and hash the password at the same time.
-            return when.join(
+            return Promise.join(
                 self.forge({email: email.toLocaleLowerCase()}).fetch({require: true}),
                 generatePasswordHash(newPassword)
             );
@@ -809,7 +812,7 @@ User = ghostBookshelf.Model.extend({
             // check if user has the owner role
             var currentRoles = ctxUser.toJSON().roles;
             if (!_.contains(currentRoles, ownerRole.id)) {
-                return when.reject(new errors.NoPermissionError('Only owners are able to transfer the owner role.'));
+                return Promise.reject(new errors.NoPermissionError('Only owners are able to transfer the owner role.'));
             }
             contextUser = ctxUser;
             return User.findOne({id: object.id});
@@ -817,7 +820,7 @@ User = ghostBookshelf.Model.extend({
 
             var currentRoles = user.toJSON().roles;
             if (!_.contains(currentRoles, adminRole.id)) {
-                return when.reject(new errors.ValidationError('Only administrators can be assigned the owner role.'));
+                return Promise.reject(new errors.ValidationError('Only administrators can be assigned the owner role.'));
             }
 
             assignUser = user;
@@ -838,20 +841,20 @@ User = ghostBookshelf.Model.extend({
     gravatarLookup: function (userData) {
         var gravatarUrl = '//www.gravatar.com/avatar/' +
                 crypto.createHash('md5').update(userData.email.toLowerCase().trim()).digest('hex') +
-                '?d=404&s=250',
-            checkPromise = when.defer();
+                '?d=404&s=250';
 
-        http.get('http:' + gravatarUrl, function (res) {
-            if (res.statusCode !== 404) {
-                userData.image = gravatarUrl;
-            }
-            checkPromise.resolve(userData);
-        }).on('error', function () {
-            //Error making request just continue.
-            checkPromise.resolve(userData);
+        return new Promise(function (resolve) {
+            http.get('http:' + gravatarUrl, function (res) {
+                if (res.statusCode !== 404) {
+                    userData.image = gravatarUrl;
+                }
+
+                resolve(userData);
+            }).on('error', function () {
+                //Error making request just continue.
+                resolve(userData);
+            });
         });
-
-        return checkPromise.promise;
     },
     // Get the user by email address, enforces case insensitivity rejects if the user is not found
     // When multi-user support is added, email addresses must be deduplicated with case insensitivity, so that
@@ -869,7 +872,7 @@ User = ghostBookshelf.Model.extend({
                 return user.get('email').toLowerCase() === email.toLowerCase();
             });
             if (userWithEmail) {
-                return when.resolve(userWithEmail);
+                return userWithEmail;
             }
         });
     }
diff --git a/core/server/permissions/index.js b/core/server/permissions/index.js
index 3cf8c3fe3d..0c7079365d 100644
--- a/core/server/permissions/index.js
+++ b/core/server/permissions/index.js
@@ -2,7 +2,7 @@
 // canThis(someUser).edit.post(somePost|somePostId)
 
 var _                   = require('lodash'),
-    when                = require('when'),
+    Promise             = require('bluebird'),
     Models              = require('../models'),
     effectivePerms      = require('./effective'),
     init,
@@ -65,7 +65,7 @@ CanThisResult.prototype.buildObjectTypeHandlers = function (obj_types, act_type,
 
             // If it's an internal request, resolve immediately
             if (context.internal) {
-                return when.resolve();
+                return Promise.resolve();
             }
 
             if (_.isNumber(modelOrId) || _.isString(modelOrId)) {
@@ -127,9 +127,10 @@ CanThisResult.prototype.buildObjectTypeHandlers = function (obj_types, act_type,
                 }
 
                 if (hasUserPermission && hasAppPermission) {
-                    return when.resolve();
+                    return;
                 }
-                return when.reject();
+
+                return Promise.reject();
             });
         };
 
@@ -155,7 +156,7 @@ CanThisResult.prototype.beginCheck = function (context) {
         userPermissionLoad = effectivePerms.user(context.user);
     } else {
         // Resolve null if no context.user to prevent db call
-        userPermissionLoad = when.resolve(null);
+        userPermissionLoad = Promise.resolve(null);
     }
 
 
@@ -164,11 +165,11 @@ CanThisResult.prototype.beginCheck = function (context) {
         appPermissionLoad = effectivePerms.app(context.app);
     } else {
         // Resolve null if no context.app
-        appPermissionLoad = when.resolve(null);
+        appPermissionLoad = Promise.resolve(null);
     }
 
     // Wait for both user and app permissions to load
-    permissionsLoad = when.all([userPermissionLoad, appPermissionLoad]).then(function (result) {
+    permissionsLoad = Promise.all([userPermissionLoad, appPermissionLoad]).then(function (result) {
         return {
             user: result[0],
             app: result[1]
@@ -232,7 +233,7 @@ init = refresh = function () {
             seenActions[action_type][object_type] = true;
         });
 
-        return when(exported.actionsMap);
+        return exported.actionsMap;
     });
 };
 
diff --git a/core/server/require-tree.js b/core/server/require-tree.js
index c384a9a18a..956ae5c067 100644
--- a/core/server/require-tree.js
+++ b/core/server/require-tree.js
@@ -1,8 +1,10 @@
 var _        = require('lodash'),
     fs       = require('fs'),
-    keys     = require('when/keys'),
     path     = require('path'),
-    when     = require('when'),
+    Promise  = require('bluebird'),
+    readdirAsync = Promise.promisify(fs.readdir),
+    lstatAsync   = Promise.promisify(fs.lstat),
+
     parsePackageJson = function (path, messages) {
         // Default the messages if non were passed
         messages = messages || {
@@ -10,42 +12,42 @@ var _        = require('lodash'),
             warns: []
         };
 
-        var packageDeferred = when.defer(),
-            packagePromise = packageDeferred.promise,
-            jsonContainer;
+        var jsonContainer;
 
-        fs.readFile(path, function (error, data) {
-            if (error) {
-                messages.errors.push({
-                    message: 'Could not read package.json file',
-                    context: path
-                });
-                packageDeferred.resolve(false);
-                return;
-            }
-            try {
-                jsonContainer = JSON.parse(data);
-                if (jsonContainer.hasOwnProperty('name') && jsonContainer.hasOwnProperty('version')) {
-                    packageDeferred.resolve(jsonContainer);
-                } else {
+        return new Promise(function (resolve) {
+            fs.readFile(path, function (error, data) {
+                if (error) {
                     messages.errors.push({
-                        message: '"name" or "version" is missing from theme package.json file.',
+                        message: 'Could not read package.json file',
+                        context: path
+                    });
+                    resolve(false);
+                    return;
+                }
+                try {
+                    jsonContainer = JSON.parse(data);
+                    if (jsonContainer.hasOwnProperty('name') && jsonContainer.hasOwnProperty('version')) {
+                        resolve(jsonContainer);
+                    } else {
+                        messages.errors.push({
+                            message: '"name" or "version" is missing from theme package.json file.',
+                            context: path,
+                            help: 'This will be required in future. Please see http://docs.ghost.org/themes/'
+                        });
+                        resolve(false);
+                    }
+                } catch (e) {
+                    messages.errors.push({
+                        message: 'Theme package.json file is malformed',
                         context: path,
                         help: 'This will be required in future. Please see http://docs.ghost.org/themes/'
                     });
-                    packageDeferred.resolve(false);
+                    resolve(false);
                 }
-            } catch (e) {
-                messages.errors.push({
-                    message: 'Theme package.json file is malformed',
-                    context: path,
-                    help: 'This will be required in future. Please see http://docs.ghost.org/themes/'
-                });
-                packageDeferred.resolve(false);
-            }
+            });
         });
-        return when(packagePromise);
     },
+
     readDir = function (dir, options, depth, messages) {
         depth = depth || 0;
         messages = messages || {
@@ -58,44 +60,29 @@ var _        = require('lodash'),
         }, options);
 
         if (depth > 1) {
-            return null;
+            return Promise.resolve(null);
         }
 
-        var subtree = {},
-            treeDeferred = when.defer(),
-            treePromise = treeDeferred.promise;
-
-        fs.readdir(dir, function (error, files) {
-            if (error) {
-                return treeDeferred.reject(error);
-            }
-
+        return readdirAsync(dir).then(function (files) {
             files = files || [];
 
-            files.forEach(function (file) {
-                var fileDeferred = when.defer(),
-                    filePromise = fileDeferred.promise,
-                    fpath = path.join(dir, file);
-                subtree[file] = filePromise;
-                fs.lstat(fpath, function (error, result) {
-                    /*jslint unparam:true*/
+            return Promise.reduce(files, function (results, file) {
+                var fpath = path.join(dir, file);
+
+                return lstatAsync(fpath).then(function (result) {
                     if (result.isDirectory()) {
-                        fileDeferred.resolve(readDir(fpath, options, depth + 1, messages));
+                        return readDir(fpath, options, depth + 1, messages);
                     } else if (depth === 1 && file === 'package.json') {
-                        fileDeferred.resolve(parsePackageJson(fpath, messages));
+                        return parsePackageJson(fpath, messages);
                     } else {
-                        fileDeferred.resolve(fpath);
+                        return fpath;
                     }
+                }).then(function (result) {
+                    results[file] = result;
+
+                    return results;
                 });
-            });
-
-            return keys.all(subtree).then(function (theFiles) {
-                return treeDeferred.resolve(theFiles);
-            });
-        });
-
-        return when(treePromise).then(function (prom) {
-            return prom;
+            }, {});
         });
     },
     readAll = function (dir, options, depth) {
@@ -105,7 +92,7 @@ var _        = require('lodash'),
             warns: []
         };
 
-        return when(readDir(dir, options, depth, messages)).then(function (paths) {
+        return readDir(dir, options, depth, messages).then(function (paths) {
             // for all contents of the dir, I'm interested in the ones that are directories and within /theme/
             if (typeof paths === 'object' && dir.indexOf('theme') !== -1) {
                 _.each(paths, function (path, index) {
@@ -118,9 +105,11 @@ var _        = require('lodash'),
                     }
                 });
             }
+
             paths._messages = messages;
+
             return paths;
-        }).otherwise(function () {
+        }).catch(function () {
             return {'_messages': messages};
         });
     };
@@ -129,4 +118,4 @@ module.exports = {
     readAll: readAll,
     readDir: readDir,
     parsePackageJson: parsePackageJson
-};
\ No newline at end of file
+};
diff --git a/core/server/storage/base.js b/core/server/storage/base.js
index d7cf63b625..1f224ca31a 100644
--- a/core/server/storage/base.js
+++ b/core/server/storage/base.js
@@ -1,6 +1,6 @@
 var moment  = require('moment'),
     path    = require('path'),
-    when    = require('when'),
+    Promise = require('bluebird'),
     baseStore;
 
 // TODO: would probably be better to put these on the prototype and have proper constructors etc
@@ -34,18 +34,18 @@ baseStore = {
                     self.generateUnique(store, dir, name, ext, i, done);
                 });
             } else {
-                done.resolve(filename);
+                done(filename);
             }
         });
     },
     'getUniqueFileName': function (store, image, targetDir) {
-        var done = when.defer(),
-            ext = path.extname(image.name),
-            name = path.basename(image.name, ext).replace(/[\W]/gi, '-');
+        var ext = path.extname(image.name),
+            name = path.basename(image.name, ext).replace(/[\W]/gi, '-'),
+            self = this;
 
-        this.generateUnique(store, targetDir, name, ext, 0, done);
-
-        return done.promise;
+        return new Promise(function (resolve) {
+            self.generateUnique(store, targetDir, name, ext, 0, resolve);
+        });
     }
 };
 
diff --git a/core/server/storage/localfilesystem.js b/core/server/storage/localfilesystem.js
index 0abd1228f4..300bf0d75b 100644
--- a/core/server/storage/localfilesystem.js
+++ b/core/server/storage/localfilesystem.js
@@ -4,9 +4,8 @@
 var _         = require('lodash'),
     express   = require('express'),
     fs        = require('fs-extra'),
-    nodefn    = require('when/node'),
     path      = require('path'),
-    when      = require('when'),
+    Promise   = require('bluebird'),
     errors    = require('../errors'),
     config    = require('../config'),
     utils     = require('../utils'),
@@ -20,37 +19,31 @@ localFileStore = _.extend(baseStore, {
     // - image is the express image object
     // - returns a promise which ultimately returns the full url to the uploaded image
     'save': function (image) {
-        var saved = when.defer(),
-            targetDir = this.getTargetDir(config.paths.imagesPath),
+        var targetDir = this.getTargetDir(config.paths.imagesPath),
             targetFilename;
 
-        this.getUniqueFileName(this, image, targetDir).then(function (filename) {
+        return this.getUniqueFileName(this, image, targetDir).then(function (filename) {
             targetFilename = filename;
-            return nodefn.call(fs.mkdirs, targetDir);
+            return Promise.promisify(fs.mkdirs)(targetDir);
         }).then(function () {
-            return nodefn.call(fs.copy, image.path, targetFilename);
+            return Promise.promisify(fs.copy)(image.path, targetFilename);
         }).then(function () {
             // The src for the image must be in URI format, not a file system path, which in Windows uses \
             // For local file system storage can use relative path so add a slash
             var fullUrl = (config.paths.subdir + '/' + config.paths.imagesRelPath + '/' + path.relative(config.paths.imagesPath, targetFilename)).replace(new RegExp('\\' + path.sep, 'g'), '/');
-            return saved.resolve(fullUrl);
-        }).otherwise(function (e) {
+            return fullUrl;
+        }).catch(function (e) {
             errors.logError(e);
-            return saved.reject(e);
+            return Promise.reject(e);
         });
-
-        return saved.promise;
     },
 
     'exists': function (filename) {
-        // fs.exists does not play nicely with nodefn because the callback doesn't have an error argument
-        var done = when.defer();
-
-        fs.exists(filename, function (exists) {
-            done.resolve(exists);
+        return new Promise(function (resolve) {
+            fs.exists(filename, function (exists) {
+                resolve(exists);
+            });
         });
-
-        return done.promise;
     },
 
     // middleware for serving the files
diff --git a/core/server/update-check.js b/core/server/update-check.js
index d132698afa..1ac8605444 100644
--- a/core/server/update-check.js
+++ b/core/server/update-check.js
@@ -23,8 +23,7 @@ var crypto   = require('crypto'),
     https    = require('https'),
     moment   = require('moment'),
     semver   = require('semver'),
-    when     = require('when'),
-    nodefn   = require('when/node'),
+    Promise  = require('bluebird'),
     _        = require('lodash'),
     url      = require('url'),
 
@@ -51,8 +50,8 @@ function updateCheckData() {
         ops = [],
         mailConfig = config.mail;
 
-    ops.push(api.settings.read(_.extend(internal, {key: 'dbHash'})).otherwise(errors.rejectError));
-    ops.push(api.settings.read(_.extend(internal, {key: 'activeTheme'})).otherwise(errors.rejectError));
+    ops.push(api.settings.read(_.extend(internal, {key: 'dbHash'})).catch(errors.rejectError));
+    ops.push(api.settings.read(_.extend(internal, {key: 'activeTheme'})).catch(errors.rejectError));
     ops.push(api.settings.read(_.extend(internal, {key: 'activeApps'}))
         .then(function (response) {
             var apps = response.settings[0];
@@ -63,10 +62,10 @@ function updateCheckData() {
             }
 
             return _.reduce(apps, function (memo, item) { return memo === '' ? memo + item : memo + ', ' + item; }, '');
-        }).otherwise(errors.rejectError));
-    ops.push(api.posts.browse().otherwise(errors.rejectError));
-    ops.push(api.users.browse(internal).otherwise(errors.rejectError));
-    ops.push(nodefn.call(exec, 'npm -v').otherwise(errors.rejectError));
+        }).catch(errors.rejectError));
+    ops.push(api.posts.browse().catch(errors.rejectError));
+    ops.push(api.users.browse(internal).catch(errors.rejectError));
+    ops.push(Promise.promisify(exec)('npm -v').catch(errors.rejectError));
 
     data.ghost_version   = currentVersion;
     data.node_version    = process.versions.node;
@@ -74,13 +73,13 @@ function updateCheckData() {
     data.database_type   = config.database.client;
     data.email_transport = mailConfig && (mailConfig.options && mailConfig.options.service ? mailConfig.options.service : mailConfig.transport);
 
-    return when.settle(ops).then(function (descriptors) {
-        var hash             = descriptors[0].value.settings[0],
-            theme            = descriptors[1].value.settings[0],
-            apps             = descriptors[2].value,
-            posts            = descriptors[3].value,
-            users            = descriptors[4].value,
-            npm              = descriptors[5].value,
+    return Promise.settle(ops).then(function (descriptors) {
+        var hash             = descriptors[0].value().settings[0],
+            theme            = descriptors[1].value().settings[0],
+            apps             = descriptors[2].value(),
+            posts            = descriptors[3].value(),
+            users            = descriptors[4].value(),
+            npm              = descriptors[5].value(),
             blogUrl          = url.parse(config.url),
             blogId           = blogUrl.hostname + blogUrl.pathname.replace(/\//, '') + hash.value;
 
@@ -93,13 +92,12 @@ function updateCheckData() {
         data.npm_version     = _.isArray(npm) && npm[0] ? npm[0].toString().replace(/\n/, '') : '';
 
         return data;
-    }).otherwise(updateCheckError);
+    }).catch(updateCheckError);
 }
 
 function updateCheckRequest() {
     return updateCheckData().then(function (reqData) {
-        var deferred = when.defer(),
-            resData = '',
+        var resData = '',
             headers,
             req;
 
@@ -109,31 +107,31 @@ function updateCheckRequest() {
             'Content-Length': reqData.length
         };
 
-        req = https.request({
-            hostname: checkEndpoint,
-            method: 'POST',
-            headers: headers
-        }, function (res) {
-            res.on('error', function (error) { deferred.reject(error); });
-            res.on('data', function (chunk) { resData += chunk; });
-            res.on('end', function () {
-                try {
-                    resData = JSON.parse(resData);
-                    deferred.resolve(resData);
-                } catch (e) {
-                    deferred.reject('Unable to decode update response');
-                }
+        return new Promise(function (resolve, reject) {
+            req = https.request({
+                hostname: checkEndpoint,
+                method: 'POST',
+                headers: headers
+            }, function (res) {
+                res.on('error', function (error) { reject(error); });
+                res.on('data', function (chunk) { resData += chunk; });
+                res.on('end', function () {
+                    try {
+                        resData = JSON.parse(resData);
+                        resolve(resData);
+                    } catch (e) {
+                        reject('Unable to decode update response');
+                    }
+                });
+            });
+
+            req.write(reqData);
+            req.end();
+
+            req.on('error', function (error) {
+                reject(error);
             });
         });
-
-        req.write(reqData);
-        req.end();
-
-        req.on('error', function (error) {
-            deferred.reject(error);
-        });
-
-        return deferred.promise;
     });
 }
 
@@ -149,53 +147,45 @@ function updateCheckResponse(response) {
         api.settings.edit(
             {settings: [{key: 'nextUpdateCheck', value: response.next_check}]},
             internal
-        )
-        .otherwise(errors.rejectError),
+        ).catch(errors.rejectError),
         api.settings.edit(
             {settings: [{key: 'displayUpdateNotification', value: response.version}]},
             internal
-        )
-        .otherwise(errors.rejectError)
+        ).catch(errors.rejectError)
     );
 
-    return when.settle(ops).then(function (descriptors) {
+    return Promise.settle(ops).then(function (descriptors) {
         descriptors.forEach(function (d) {
-            if (d.state === 'rejected') {
-                errors.rejectError(d.reason);
+            if (d.isRejected()) {
+                errors.rejectError(d.reason());
             }
         });
-        return when.resolve();
     });
 }
 
 function updateCheck() {
-    var deferred = when.defer();
-
     // The check will not happen if:
     // 1. updateCheck is defined as false in config.js
     // 2. we've already done a check this session
     // 3. we're not in production or development mode
     if (config.updateCheck === false || _.indexOf(allowedCheckEnvironments, process.env.NODE_ENV) === -1) {
         // No update check
-        deferred.resolve();
+        return Promise.resolve();
     } else {
-        api.settings.read(_.extend(internal, {key: 'nextUpdateCheck'})).then(function (result) {
+        return api.settings.read(_.extend(internal, {key: 'nextUpdateCheck'})).then(function (result) {
             var nextUpdateCheck = result.settings[0];
 
             if (nextUpdateCheck && nextUpdateCheck.value && nextUpdateCheck.value > moment().unix()) {
                 // It's not time to check yet
-                deferred.resolve();
+                return;
             } else {
                 // We need to do a check
                 return updateCheckRequest()
                     .then(updateCheckResponse)
-                    .otherwise(updateCheckError);
+                    .catch(updateCheckError);
             }
-        }).otherwise(updateCheckError)
-            .then(deferred.resolve);
+        }).catch(updateCheckError);
     }
-
-    return deferred.promise;
 }
 
 function showUpdateNotification() {
@@ -210,9 +200,10 @@ function showUpdateNotification() {
         }
 
         if (display && display.value && currentVersion && semver.gt(display.value, currentVersion)) {
-            return when(display.value);
+            return display.value;
         }
-        return when(false);
+
+        return false;
     });
 }
 
diff --git a/core/server/utils/pipeline.js b/core/server/utils/pipeline.js
new file mode 100644
index 0000000000..513a4ea540
--- /dev/null
+++ b/core/server/utils/pipeline.js
@@ -0,0 +1,21 @@
+var Promise = require('bluebird');
+
+function pipeline(tasks /* initial arguments */) {
+    var args = Array.prototype.slice.call(arguments, 1),
+
+        runTask = function (task, args) {
+            runTask = function (task, arg) {
+                return task(arg);
+            };
+
+            return task.apply(null, args);
+        };
+
+    return Promise.all(tasks).reduce(function (arg, task) {
+        return Promise.resolve(runTask(task, arg)).then(function (result) {
+            return result;
+        });
+    }, args);
+}
+
+module.exports = pipeline;
diff --git a/core/server/utils/sequence.js b/core/server/utils/sequence.js
new file mode 100644
index 0000000000..6040b5dda2
--- /dev/null
+++ b/core/server/utils/sequence.js
@@ -0,0 +1,13 @@
+var Promise = require('bluebird');
+
+function sequence(tasks) {
+    return Promise.reduce(tasks, function (results, task) {
+        return task().then(function (result) {
+            results.push(result);
+
+            return results;
+        });
+    }, []);
+}
+
+module.exports = sequence;
diff --git a/core/test/functional/routes/admin_test.js b/core/test/functional/routes/admin_test.js
index 17ccde3bfb..b5a5d6345c 100644
--- a/core/test/functional/routes/admin_test.js
+++ b/core/test/functional/routes/admin_test.js
@@ -62,7 +62,7 @@ describe('Admin Routing', function () {
             }).then(function () {
                 done();
             }).catch(done);
-        }).otherwise(function (e) {
+        }).catch(function (e) {
             console.log('Ghost Error: ', e);
             console.log(e.stack);
         });
@@ -332,7 +332,7 @@ describe('Admin Routing', function () {
 
 //                         });
 //                 }).catch(done);
-//         }).otherwise(function (e) {
+//         }).catch(function (e) {
 //             console.log('Ghost Error: ', e);
 //             console.log(e.stack);
 //         });
diff --git a/core/test/functional/routes/api/users_test.js b/core/test/functional/routes/api/users_test.js
index 6dbf9afb0f..7760465eff 100644
--- a/core/test/functional/routes/api/users_test.js
+++ b/core/test/functional/routes/api/users_test.js
@@ -334,7 +334,8 @@ describe('User API', function () {
 
                     var jsonResponse = res.body,
                         changedValue = 'joe-bloggs.ghost.org';
-                    jsonResponse.users[0].should.exist;
+
+                    should.exist(jsonResponse.users[0]);
                     jsonResponse.users[0].website = changedValue;
 
                     request.put(testUtils.API.getApiQuery('users/me/'))
diff --git a/core/test/integration/api/api_authentication_spec.js b/core/test/integration/api/api_authentication_spec.js
index 5d67a50987..9959a3d648 100644
--- a/core/test/integration/api/api_authentication_spec.js
+++ b/core/test/integration/api/api_authentication_spec.js
@@ -2,7 +2,7 @@
 /*jshint expr:true*/
 var testUtils   = require('../../utils'),
     should      = require('should'),
-    when        = require('when'),
+    Promise     = require('bluebird'),
     rewire      = require('rewire'),
 
     // Stuff we are testing
@@ -43,7 +43,7 @@ describe('Authentication API', function () {
                 send = mail.__get__('mail.send');
 
                 mail.__set__('mail.send', function () {
-                    return when.resolve();
+                    return Promise.resolve();
                 });
 
                 AuthAPI.setup({ setup: [setupData] }).then(function (result) {
diff --git a/core/test/integration/api/api_themes_spec.js b/core/test/integration/api/api_themes_spec.js
index 94d0435057..af8ac459b1 100644
--- a/core/test/integration/api/api_themes_spec.js
+++ b/core/test/integration/api/api_themes_spec.js
@@ -5,7 +5,7 @@ var _             = require('lodash'),
     rewire        = require('rewire'),
     should        = require('should'),
     sinon         = require('sinon'),
-    when          = require('when'),
+    Promise       = require('bluebird'),
 
     // Stuff we are testing
     SettingsAPI   = require('../../../server/api/settings'),
@@ -30,11 +30,11 @@ describe('Themes API', function () {
     beforeEach(function () {
         // Override settings.read for activeTheme
         sandbox.stub(SettingsAPI, 'read', function () {
-            return when({ settings: [{value: 'casper'}] });
+            return Promise.resolve({ settings: [{value: 'casper'}] });
         });
 
         sandbox.stub(SettingsAPI, 'edit', function () {
-            return when({ settings: [{value: 'rasper'}] });
+            return Promise.resolve({ settings: [{value: 'rasper'}] });
         });
 
         configStub = {
diff --git a/core/test/integration/api/api_upload_spec.js b/core/test/integration/api/api_upload_spec.js
index 43986a735e..970564ec93 100644
--- a/core/test/integration/api/api_upload_spec.js
+++ b/core/test/integration/api/api_upload_spec.js
@@ -3,7 +3,7 @@
 var fs          = require('fs-extra'),
     should      = require('should'),
     sinon       = require('sinon'),
-    when        = require('when'),
+    Promise     = require('bluebird'),
     storage     = require('../../../server/storage'),
 
     // Stuff we are testing
@@ -23,9 +23,9 @@ describe('Upload API', function () {
 
     beforeEach(function () {
         store = sinon.stub();
-        store.save = sinon.stub().returns(when('URL'));
-        store.exists = sinon.stub().returns(when(true));
-        store.destroy = sinon.stub().returns(when());
+        store.save = sinon.stub().returns(Promise.resolve('URL'));
+        store.exists = sinon.stub().returns(Promise.resolve(true));
+        store.destroy = sinon.stub().returns(Promise.resolve());
         sinon.stub(storage, 'get_storage').returns(store);
         sinon.stub(fs, 'unlink').yields();
     });
diff --git a/core/test/integration/api/api_users_spec.js b/core/test/integration/api/api_users_spec.js
index c0ab6ef43f..df51b5d60a 100644
--- a/core/test/integration/api/api_users_spec.js
+++ b/core/test/integration/api/api_users_spec.js
@@ -3,7 +3,7 @@
 var testUtils   = require('../../utils'),
     should      = require('should'),
     sinon       = require('sinon'),
-    when        = require('when'),
+    Promise     = require('bluebird'),
     _           = require('lodash'),
 
 // Stuff we are testing
@@ -340,11 +340,11 @@ describe('Users API', function () {
             newUser = _.clone(testUtils.DataGenerator.forKnex.createUser(testUtils.DataGenerator.Content.users[4]));
 
             sandbox.stub(ModelUser.User, 'gravatarLookup', function (userData) {
-                return when.resolve(userData);
+                return Promise.resolve(userData);
             });
 
             sandbox.stub(mail, 'send', function () {
-                return when.resolve();
+                return Promise.resolve();
             });
         });
         afterEach(function () {
@@ -933,11 +933,11 @@ describe('Users API', function () {
                         {name: newName, roles: [roleIdFor.admin]}
                     ]}, _.extend({}, context.editor, {id: userIdFor.author}, {include: 'roles'})
                 ).then(function (response) {
-                        done(new Error('Editor should not be able to upgrade the role of authors'));
-                    }, function (error) {
-                        error.type.should.eql('NoPermissionError');
-                        done();
-                    }).catch(done);
+                    done(new Error('Editor should not be able to upgrade the role of authors'));
+                }).catch(function (error) {
+                    error.type.should.eql('NoPermissionError');
+                    done();
+                }).catch(done);
             });
         });
 
diff --git a/core/test/integration/export_spec.js b/core/test/integration/export_spec.js
index 480b8031bf..dfadb4b043 100644
--- a/core/test/integration/export_spec.js
+++ b/core/test/integration/export_spec.js
@@ -3,7 +3,7 @@
 var testUtils   = require('../utils/index'),
     should      = require('should'),
     sinon       = require('sinon'),
-    when        = require('when'),
+    Promise     = require('bluebird'),
     _           = require('lodash'),
 
     // Stuff we are testing
@@ -25,7 +25,7 @@ describe('Exporter', function () {
     it('exports data', function (done) {
         // Stub migrations to return 000 as the current database version
         var versioningStub = sandbox.stub(versioning, 'getDatabaseVersion', function () {
-            return when.resolve('003');
+            return Promise.resolve('003');
         });
 
         exporter().then(function (exportData) {
diff --git a/core/test/integration/import_spec.js b/core/test/integration/import_spec.js
index ae2fef52d2..3f3f5b8262 100644
--- a/core/test/integration/import_spec.js
+++ b/core/test/integration/import_spec.js
@@ -3,7 +3,7 @@
 var testUtils   = require('../utils/index'),
     should      = require('should'),
     sinon       = require('sinon'),
-    when        = require('when'),
+    Promise     = require('bluebird'),
     assert      = require('assert'),
     _           = require('lodash'),
     rewire      = require('rewire'),
@@ -48,7 +48,7 @@ describe('Import', function () {
 
         it('resolves 000', function (done) {
             var importStub = sandbox.stub(Importer000, 'importData', function () {
-                    return when.resolve();
+                    return Promise.resolve();
                 }),
                 fakeData = { test: true };
 
@@ -63,7 +63,7 @@ describe('Import', function () {
 
         it('resolves 001', function (done) {
             var importStub = sandbox.stub(Importer001, 'importData', function () {
-                    return when.resolve();
+                    return Promise.resolve();
                 }),
                 fakeData = { test: true };
 
@@ -78,7 +78,7 @@ describe('Import', function () {
 
         it('resolves 002', function (done) {
             var importStub = sandbox.stub(Importer002, 'importData', function () {
-                    return when.resolve();
+                    return Promise.resolve();
                 }),
                 fakeData = { test: true };
 
@@ -93,7 +93,7 @@ describe('Import', function () {
 
         it('resolves 003', function (done) {
             var importStub = sandbox.stub(Importer003, 'importData', function () {
-                    return when.resolve();
+                    return Promise.resolve();
                 }),
                 fakeData = { test: true };
 
@@ -118,7 +118,7 @@ describe('Import', function () {
         it('imports data from 000', function (done) {
             var exportData,
                 versioningStub = sandbox.stub(versioning, 'getDatabaseVersion', function () {
-                    return when.resolve('000');
+                    return Promise.resolve('000');
                 });
 
             testUtils.fixtures.loadExportFixture('export-000').then(function (exported) {
@@ -127,7 +127,7 @@ describe('Import', function () {
                 return importer('000', exportData);
             }).then(function () {
                 // Grab the data from tables
-                return when.all([
+                return Promise.all([
                     knex('users').select(),
                     knex('posts').select(),
                     knex('settings').select(),
@@ -186,7 +186,7 @@ describe('Import', function () {
                 return importer('001', exportData);
             }).then(function () {
                 // Grab the data from tables
-                return when.all([
+                return Promise.all([
                     knex('users').select(),
                     knex('posts').select(),
                     knex('settings').select(),
@@ -261,7 +261,7 @@ describe('Import', function () {
                 error[0].message.should.eql('Value in [posts.title] exceeds maximum length of 150 characters.');
                 error[0].type.should.eql('ValidationError');
 
-                when.all([
+                Promise.all([
                     knex('users').select(),
                     knex('posts').select(),
                     knex('settings').select(),
@@ -310,7 +310,7 @@ describe('Import', function () {
                 error[0].message.should.eql('Value in [settings.key] cannot be blank.');
                 error[0].type.should.eql('ValidationError');
 
-                when.all([
+                Promise.all([
                     knex('users').select(),
                     knex('posts').select(),
                     knex('settings').select(),
@@ -367,7 +367,7 @@ describe('Import', function () {
                 return importer('002', exportData);
             }).then(function () {
                 // Grab the data from tables
-                return when.all([
+                return Promise.all([
                     knex('users').select(),
                     knex('posts').select(),
                     knex('settings').select(),
@@ -443,7 +443,7 @@ describe('Import', function () {
                 error[0].message.should.eql('Value in [posts.title] exceeds maximum length of 150 characters.');
                 error[0].type.should.eql('ValidationError');
 
-                when.all([
+                Promise.all([
                     knex('users').select(),
                     knex('posts').select(),
                     knex('settings').select(),
@@ -489,7 +489,7 @@ describe('Import', function () {
                 error[0].message.should.eql('Value in [settings.key] cannot be blank.');
                 error[0].type.should.eql('ValidationError');
 
-                when.all([
+                Promise.all([
                     knex('users').select(),
                     knex('posts').select(),
                     knex('settings').select(),
@@ -537,7 +537,7 @@ describe('Import', function () {
                 return importer('003', exportData);
             }).then(function () {
                 // Grab the data from tables
-                return when.all([
+                return Promise.all([
                     knex('users').select(),
                     knex('posts').select(),
                     knex('settings').select(),
@@ -704,7 +704,7 @@ describe('Import (new test structure)', function () {
             after(testUtils.teardown);
 
             it('gets the right data', function (done) {
-                var fetchImported = when.join(
+                var fetchImported = Promise.join(
                     knex('posts').select(),
                     knex('settings').select(),
                     knex('tags').select()
@@ -755,7 +755,7 @@ describe('Import (new test structure)', function () {
             });
 
             it('imports users with correct roles and status', function (done) {
-                var fetchImported = when.join(
+                var fetchImported = Promise.join(
                     knex('users').select(),
                     knex('roles_users').select()
                 );
@@ -829,7 +829,7 @@ describe('Import (new test structure)', function () {
             });
 
             it('imports posts & tags with correct authors, owners etc', function (done) {
-                var fetchImported = when.join(
+                var fetchImported = Promise.join(
                     knex('users').select(),
                     knex('posts').select(),
                     knex('tags').select()
@@ -931,7 +931,7 @@ describe('Import (new test structure)', function () {
                     after(testUtils.teardown);
 
                     it('gets the right data', function (done) {
-                        var fetchImported = when.join(
+                        var fetchImported = Promise.join(
                             knex('posts').select(),
                             knex('settings').select(),
                             knex('tags').select()
@@ -982,7 +982,7 @@ describe('Import (new test structure)', function () {
                     });
 
                     it('imports users with correct roles and status', function (done) {
-                        var fetchImported = when.join(
+                        var fetchImported = Promise.join(
                             knex('users').select(),
                             knex('roles_users').select()
                         );
@@ -1056,7 +1056,7 @@ describe('Import (new test structure)', function () {
                     });
 
                     it('imports posts & tags with correct authors, owners etc', function (done) {
-                        var fetchImported = when.join(
+                        var fetchImported = Promise.join(
                             knex('users').select(),
                             knex('posts').select(),
                             knex('tags').select()
@@ -1159,7 +1159,7 @@ describe('Import (new test structure)', function () {
             after(testUtils.teardown);
 
             it('gets the right data', function (done) {
-                var fetchImported = when.join(
+                var fetchImported = Promise.join(
                     knex('posts').select(),
                     knex('settings').select(),
                     knex('tags').select()
@@ -1221,7 +1221,7 @@ describe('Import (new test structure)', function () {
             });
 
             it('imports users with correct roles and status', function (done) {
-                var fetchImported = when.join(
+                var fetchImported = Promise.join(
                     knex('users').select(),
                     knex('roles_users').select()
                 );
@@ -1290,7 +1290,7 @@ describe('Import (new test structure)', function () {
             });
 
             it('imports posts & tags with correct authors, owners etc', function (done) {
-                var fetchImported = when.join(
+                var fetchImported = Promise.join(
                     knex('users').select(),
                     knex('posts').select(),
                     knex('tags').select()
diff --git a/core/test/integration/model/model_apps_spec.js b/core/test/integration/model/model_apps_spec.js
index 5fd6d2f241..eecf622ac7 100644
--- a/core/test/integration/model/model_apps_spec.js
+++ b/core/test/integration/model/model_apps_spec.js
@@ -2,7 +2,8 @@
 /*jshint expr:true*/
 var testUtils    = require('../../utils'),
     should       = require('should'),
-    sequence     = require('when/sequence'),
+    Promise      = require('bluebird'),
+    sequence     = require('../../../server/utils/sequence'),
     _            = require('lodash'),
 
     // Stuff we are testing
diff --git a/core/test/integration/model/model_posts_spec.js b/core/test/integration/model/model_posts_spec.js
index 02c672d783..c6220a5df3 100644
--- a/core/test/integration/model/model_posts_spec.js
+++ b/core/test/integration/model/model_posts_spec.js
@@ -2,7 +2,8 @@
 /*jshint expr:true*/
 var testUtils       = require('../../utils'),
     should          = require('should'),
-    sequence        = require('when/sequence'),
+    Promise         = require('bluebird'),
+    sequence        = require('../../../server/utils/sequence'),
     _               = require('lodash'),
 
     // Stuff we are testing
@@ -541,6 +542,6 @@ describe('Post Model', function () {
     //    }).then(function (saved) {
     //        saved.get('title').should.eql("&lt;/title&gt;&lt;/head>&lt;body&gt;[removed]alert&#40;'blogtitle'&#41;;[removed]");
     //        done();
-    //    }).otherwise(done);
+    //    }).catch(done);
     // });
 });
diff --git a/core/test/integration/model/model_tags_spec.js b/core/test/integration/model/model_tags_spec.js
index d5d9841da2..5cb2e336ce 100644
--- a/core/test/integration/model/model_tags_spec.js
+++ b/core/test/integration/model/model_tags_spec.js
@@ -2,7 +2,7 @@
 /*jshint expr:true*/
 var testUtils   = require('../../utils'),
     should      = require('should'),
-    when        = require('when'),
+    Promise     = require('bluebird'),
     _           = require('lodash'),
 
     // Stuff we are testing
@@ -44,7 +44,7 @@ describe('Tag Model', function () {
                 newTag = testUtils.DataGenerator.forModel.tags[0],
                 createdPostID;
 
-            when.all([
+            Promise.all([
                 PostModel.add(newPost, context),
                 TagModel.add(newTag, context)
             ]).then(function (models) {
@@ -71,7 +71,7 @@ describe('Tag Model', function () {
                 createdTagID,
                 createdPostID;
 
-            when.all([
+            Promise.all([
                 PostModel.add(newPost, context),
                 TagModel.add(newTag, context)
             ]).then(function (models) {
@@ -106,7 +106,7 @@ describe('Tag Model', function () {
                 var tagModels = tagNames.map(function (tagName) { return TagModel.add({name: tagName}, context); });
                 createOperations = createOperations.concat(tagModels);
 
-                return when.all(createOperations).then(function (models) {
+                return Promise.all(createOperations).then(function (models) {
                     var postModel = models[0],
                         attachOperations;
 
@@ -115,7 +115,7 @@ describe('Tag Model', function () {
                         attachOperations.push(postModel.tags().attach(models[i]));
                     }
 
-                    return when.all(attachOperations).then(function () {
+                    return Promise.all(attachOperations).then(function () {
                         return postModel;
                     });
                 }).then(function (postModel) {
diff --git a/core/test/integration/model/model_users_spec.js b/core/test/integration/model/model_users_spec.js
index 2317feca89..5438181649 100644
--- a/core/test/integration/model/model_users_spec.js
+++ b/core/test/integration/model/model_users_spec.js
@@ -2,7 +2,7 @@
 /*jshint expr:true*/
 var testUtils   = require('../../utils'),
     should      = require('should'),
-    when        = require('when'),
+    Promise     = require('bluebird'),
     sinon       = require('sinon'),
     uuid        = require('node-uuid'),
     _           = require('lodash'),
@@ -33,7 +33,7 @@ describe('User Model', function run() {
             var userData = testUtils.DataGenerator.forModel.users[0];
 
             sandbox.stub(UserModel, 'gravatarLookup', function (userData) {
-                return when.resolve(userData);
+                return Promise.resolve(userData);
             });
 
             UserModel.add(userData, context).then(function (createdUser) {
@@ -50,7 +50,7 @@ describe('User Model', function run() {
             var userData = testUtils.DataGenerator.forModel.users[2];
 
             sandbox.stub(UserModel, 'gravatarLookup', function (userData) {
-                return when.resolve(userData);
+                return Promise.resolve(userData);
             });
 
             UserModel.add(userData, context).then(function (createdUser) {
@@ -66,7 +66,7 @@ describe('User Model', function run() {
 
             sandbox.stub(UserModel, 'gravatarLookup', function (userData) {
                 userData.image = 'http://www.gravatar.com/avatar/2fab21a4c4ed88e76add10650c73bae1?d=404';
-                return when.resolve(userData);
+                return Promise.resolve(userData);
             });
 
             UserModel.add(userData, context).then(function (createdUser) {
@@ -83,7 +83,7 @@ describe('User Model', function run() {
             var userData = testUtils.DataGenerator.forModel.users[0];
 
             sandbox.stub(UserModel, 'gravatarLookup', function (userData) {
-                return when.resolve(userData);
+                return Promise.resolve(userData);
             });
 
             UserModel.add(userData, context).then(function (createdUser) {
@@ -271,7 +271,7 @@ describe('User Model', function run() {
             var userData = testUtils.DataGenerator.forModel.users[4];
 
             sandbox.stub(UserModel, 'gravatarLookup', function (userData) {
-                return when.resolve(userData);
+                return Promise.resolve(userData);
             });
 
             RoleModel.findOne().then(function (role) {
diff --git a/core/test/unit/apps_spec.js b/core/test/unit/apps_spec.js
index b6ad4f5e57..a27c705b33 100644
--- a/core/test/unit/apps_spec.js
+++ b/core/test/unit/apps_spec.js
@@ -5,7 +5,7 @@ var path         = require('path'),
     should       = require('should'),
     sinon        = require('sinon'),
     _            = require('lodash'),
-    when         = require('when'),
+    Promise      = require('bluebird'),
     helpers      = require('../../server/helpers'),
     filters      = require('../../server/filters'),
 
@@ -432,7 +432,7 @@ describe('Apps', function () {
             var perms = new AppPermissions("test");
 
             // No package.json in this directory
-            sandbox.stub(perms, "checkPackageContentsExists").returns(when.resolve(false));
+            sandbox.stub(perms, "checkPackageContentsExists").returns(Promise.resolve(false));
 
             perms.read().then(function (readPerms) {
                 should.exist(readPerms);
@@ -447,9 +447,9 @@ describe('Apps', function () {
                 noGhostPackageJsonContents = JSON.stringify(noGhostPackageJson, null, 2);
 
             // package.json IS in this directory
-            sandbox.stub(perms, "checkPackageContentsExists").returns(when.resolve(true));
+            sandbox.stub(perms, "checkPackageContentsExists").returns(Promise.resolve(true));
             // no ghost property on package
-            sandbox.stub(perms, "getPackageContents").returns(when.resolve(noGhostPackageJsonContents));
+            sandbox.stub(perms, "getPackageContents").returns(Promise.resolve(noGhostPackageJsonContents));
 
             perms.read().then(function (readPerms) {
                 should.exist(readPerms);
@@ -463,9 +463,9 @@ describe('Apps', function () {
             var perms = new AppPermissions("test");
 
             // package.json IS in this directory
-            sandbox.stub(perms, "checkPackageContentsExists").returns(when.resolve(true));
+            sandbox.stub(perms, "checkPackageContentsExists").returns(Promise.resolve(true));
             // malformed JSON on package
-            sandbox.stub(perms, "getPackageContents").returns(when.reject(new Error('package.json file is malformed')));
+            sandbox.stub(perms, "getPackageContents").returns(Promise.reject(new Error('package.json file is malformed')));
 
             perms.read().then(function (readPerms) {
                 /*jshint unused:false*/
@@ -480,9 +480,9 @@ describe('Apps', function () {
                 validGhostPackageJsonContents = validGhostPackageJson;
 
             // package.json IS in this directory
-            sandbox.stub(perms, "checkPackageContentsExists").returns(when.resolve(true));
+            sandbox.stub(perms, "checkPackageContentsExists").returns(Promise.resolve(true));
             // valid ghost property on package
-            sandbox.stub(perms, "getPackageContents").returns(when.resolve(validGhostPackageJsonContents));
+            sandbox.stub(perms, "getPackageContents").returns(Promise.resolve(validGhostPackageJsonContents));
 
             perms.read().then(function (readPerms) {
                 should.exist(readPerms);
diff --git a/core/test/unit/bootstrap_spec.js b/core/test/unit/bootstrap_spec.js
index 97ad68b620..6e6906125e 100644
--- a/core/test/unit/bootstrap_spec.js
+++ b/core/test/unit/bootstrap_spec.js
@@ -2,7 +2,7 @@
 /*jshint expr:true*/
 var should         = require('should'),
     sinon          = require('sinon'),
-    when           = require('when'),
+    Promise        = require('bluebird'),
     path           = require('path'),
     fs             = require('fs'),
     _              = require('lodash'),
@@ -62,13 +62,10 @@ describe('Bootstrap', function () {
 
     it('creates the config file if one does not exist', function (done) {
 
-        var deferred = when.defer(),
             // trick bootstrap into thinking that the config file doesn't exist yet
-            existsStub  = sandbox.stub(fs, 'exists', function (file, cb) { return cb(false); }),
+        var existsStub = sandbox.stub(fs, 'exists', function (file, cb) { return cb(false); }),
             // create a method which will return a pre-resolved promise
-            resolvedPromise = sandbox.stub().returns(deferred.promise);
-
-        deferred.resolve();
+            resolvedPromise = sandbox.stub().returns(Promise.resolve());
 
         // ensure that the file creation is a stub, the tests shouldn't really create a file
         bootstrap.__set__('writeConfigFile',  resolvedPromise);
diff --git a/core/test/unit/config_spec.js b/core/test/unit/config_spec.js
index e0066cff64..3e3b84eb30 100644
--- a/core/test/unit/config_spec.js
+++ b/core/test/unit/config_spec.js
@@ -2,7 +2,7 @@
 /*jshint expr:true*/
 var should         = require('should'),
     sinon          = require('sinon'),
-    when           = require('when'),
+    Promise        = require('bluebird'),
     path           = require('path'),
     _              = require('lodash'),
     rewire         = require('rewire'),
@@ -32,7 +32,7 @@ describe('Config', function () {
             settings = {'read': function read() {}};
 
             settingsStub = sandbox.stub(settings, 'read', function () {
-                return when({ settings: [{value: 'casper'}] });
+                return Promise.resolve({ settings: [{value: 'casper'}] });
             });
 
             theme.update(settings, 'http://my-ghost-blog.com')
@@ -270,7 +270,7 @@ describe('Config', function () {
         it('should output correct url for post', function (done) {
             var settings = {'read': function read() {}},
                 settingsStub = sandbox.stub(settings, 'read', function () {
-                    return when({ settings: [{value: '/:slug/'}] });
+                    return Promise.resolve({ settings: [{value: '/:slug/'}] });
                 }),
                 /*jshint unused:false*/
                 testData = testUtils.DataGenerator.Content.posts[2],
@@ -308,7 +308,7 @@ describe('Config', function () {
         it('should output correct url for post with date permalink', function (done) {
             var settings = {'read': function read() {}},
                 settingsStub = sandbox.stub(settings, 'read', function () {
-                    return when({ settings: [{value: '/:year/:month/:day/:slug/'}] });
+                    return Promise.resolve({ settings: [{value: '/:year/:month/:day/:slug/'}] });
                 }),
                 /*jshint unused:false*/
                 testData = testUtils.DataGenerator.Content.posts[2],
@@ -349,7 +349,7 @@ describe('Config', function () {
         it('should output correct url for page with date permalink', function (done) {
             var settings = {'read': function read() {}},
                 settingsStub = sandbox.stub(settings, 'read', function () {
-                    return when({ settings: [{value: '/:year/:month/:day/:slug/'}] });
+                    return Promise.resolve({ settings: [{value: '/:year/:month/:day/:slug/'}] });
                 }),
                 /*jshint unused:false*/
                 testData = testUtils.DataGenerator.Content.posts[5],
diff --git a/core/test/unit/errorHandling_spec.js b/core/test/unit/errorHandling_spec.js
index 8e393712a3..840a0388b9 100644
--- a/core/test/unit/errorHandling_spec.js
+++ b/core/test/unit/errorHandling_spec.js
@@ -1,7 +1,7 @@
 /*globals describe, after, before, beforeEach, afterEach, it*/
 /*jshint expr:true*/
 var should     = require('should'),
-    when       = require('when'),
+    Promise    = require('bluebird'),
     sinon      = require('sinon'),
     express    = require('express'),
     rewire     = require('rewire'),
@@ -181,9 +181,7 @@ describe('Error handling', function () {
         });
 
         it('logs promise errors and redirects', function (done) {
-            var def = when.defer(),
-                prom = def.promise,
-                req = null,
+            var req = null,
                 res = {
                     redirect: function () {
                         return;
@@ -192,11 +190,11 @@ describe('Error handling', function () {
                 redirectStub = sinon.stub(res, 'redirect');
 
             // give environment a value that will console log
-            prom.then(function () {
+            Promise.reject().then(function () {
                 throw new Error('Ran success handler');
             }, errors.logErrorWithRedirect('test1', null, null, '/testurl', req, res));
 
-            prom.otherwise(function () {
+            Promise.reject().catch(function () {
                 logStub.calledWith('\nERROR:'.red, 'test1'.red).should.equal(true);
                 logStub.restore();
 
@@ -205,7 +203,6 @@ describe('Error handling', function () {
 
                 done();
             });
-            def.reject();
         });
     });
 
diff --git a/core/test/unit/filters_spec.js b/core/test/unit/filters_spec.js
index 2736ab8e5a..4be09dc003 100644
--- a/core/test/unit/filters_spec.js
+++ b/core/test/unit/filters_spec.js
@@ -2,7 +2,7 @@
 /*jshint expr:true*/
 var should  = require('should'),
     sinon   = require('sinon'),
-    when    = require('when'),
+    Promise = require('bluebird'),
     _       = require('lodash'),
 
     // Stuff we are testing
@@ -85,7 +85,7 @@ describe('Filters', function () {
     it('executes filters that return a promise', function (done) {
         var filterName = 'testprioritypromise',
             testFilterHandler1 = sinon.spy(function (args) {
-                return when.promise(function (resolve) {
+                return new Promise(function (resolve) {
                     process.nextTick(function () {
                         args.filter1 = true;
 
@@ -99,7 +99,7 @@ describe('Filters', function () {
                 return args;
             }),
             testFilterHandler3 = sinon.spy(function (args) {
-                return when.promise(function (resolve) {
+                return new Promise(function (resolve) {
                     process.nextTick(function () {
                         args.filter3 = true;
 
diff --git a/core/test/unit/frontend_spec.js b/core/test/unit/frontend_spec.js
index 91d7dfcf2a..e0e7dceb74 100644
--- a/core/test/unit/frontend_spec.js
+++ b/core/test/unit/frontend_spec.js
@@ -4,7 +4,7 @@ var assert   = require('assert'),
     moment   = require('moment'),
     should   = require('should'),
     sinon    = require('sinon'),
-    when     = require('when'),
+    Promise  = require('bluebird'),
     rewire   = require('rewire'),
     _        = require('lodash'),
 
@@ -53,11 +53,11 @@ describe('Frontend Controller', function () {
             };
 
             sandbox.stub(api.posts, 'browse', function () {
-                return when({posts: {}, meta: {pagination: { pages: 3}}});
+                return Promise.resolve({posts: {}, meta: {pagination: { pages: 3}}});
             });
 
             apiSettingsStub = sandbox.stub(api.settings, 'read');
-            apiSettingsStub.withArgs('postsPerPage').returns(when({
+            apiSettingsStub.withArgs('postsPerPage').returns(Promise.resolve({
                 settings: [{
                     'key': 'postsPerPage',
                     'value': 5
@@ -156,7 +156,7 @@ describe('Frontend Controller', function () {
 
         beforeEach(function () {
             sandbox.stub(api.posts, 'browse', function () {
-                return when({
+                return Promise.resolve({
                     posts: [],
                     meta: {
                         pagination: {
@@ -169,14 +169,14 @@ describe('Frontend Controller', function () {
 
             apiSettingsStub = sandbox.stub(api.settings, 'read');
 
-            apiSettingsStub.withArgs(sinon.match.has('key', 'activeTheme')).returns(when({
+            apiSettingsStub.withArgs(sinon.match.has('key', 'activeTheme')).returns(Promise.resolve({
                 settings: [{
                     'key': 'activeTheme',
                     'value': 'casper'
                 }]
             }));
 
-            apiSettingsStub.withArgs('postsPerPage').returns(when({
+            apiSettingsStub.withArgs('postsPerPage').returns(Promise.resolve({
                 settings: [{
                     'key': 'postsPerPage',
                     'value': '10'
@@ -306,7 +306,7 @@ describe('Frontend Controller', function () {
 
         beforeEach(function () {
             sandbox.stub(api.posts, 'browse', function () {
-                return when({
+                return Promise.resolve({
                     posts: mockPosts,
                     meta: {
                         pagination: {
@@ -322,14 +322,14 @@ describe('Frontend Controller', function () {
 
             apiSettingsStub = sandbox.stub(api.settings, 'read');
 
-            apiSettingsStub.withArgs(sinon.match.has('key', 'activeTheme')).returns(when({
+            apiSettingsStub.withArgs(sinon.match.has('key', 'activeTheme')).returns(Promise.resolve({
                 settings: [{
                     'key': 'activeTheme',
                     'value': 'casper'
                 }]
             }));
 
-            apiSettingsStub.withArgs('postsPerPage').returns(when({
+            apiSettingsStub.withArgs('postsPerPage').returns(Promise.resolve({
                 settings: [{
                     'key': 'postsPerPage',
                     'value': '10'
@@ -355,7 +355,7 @@ describe('Frontend Controller', function () {
         describe('custom tag template', function () {
 
             beforeEach(function () {
-                apiSettingsStub.withArgs('permalinks').returns(when({
+                apiSettingsStub.withArgs('permalinks').returns(Promise.resolve({
                     settings: [{
                         key: 'permalinks',
                         value: '/tag/:slug/'
@@ -392,11 +392,11 @@ describe('Frontend Controller', function () {
             };
 
             sandbox.stub(api.posts, 'browse', function () {
-                return when({posts: {}, meta: {pagination: { pages: 3}}});
+                return Promise.resolve({posts: {}, meta: {pagination: { pages: 3}}});
             });
 
             apiSettingsStub = sandbox.stub(api.settings, 'read');
-            apiSettingsStub.withArgs('postsPerPage').returns(when({
+            apiSettingsStub.withArgs('postsPerPage').returns(Promise.resolve({
                 settings: [{
                     'key': 'postsPerPage',
                     'value': 5
@@ -542,14 +542,14 @@ describe('Frontend Controller', function () {
 
         beforeEach(function () {
             sandbox.stub(api.posts, 'read', function (args) {
-                return when(_.find(mockPosts, function(mock) {
+                return Promise.resolve(_.find(mockPosts, function(mock) {
                     return mock.posts[0].slug === args.slug;
                 }));
             });
 
             apiSettingsStub = sandbox.stub(api.settings, 'read');
 
-            apiSettingsStub.withArgs(sinon.match.has('key', 'activeTheme')).returns(when({
+            apiSettingsStub.withArgs(sinon.match.has('key', 'activeTheme')).returns(Promise.resolve({
                 settings: [{
                     'key': 'activeTheme',
                     'value': 'casper'
@@ -577,7 +577,7 @@ describe('Frontend Controller', function () {
 
             describe('custom page templates', function () {
                 beforeEach(function () {
-                    apiSettingsStub.withArgs('permalinks').returns(when({
+                    apiSettingsStub.withArgs('permalinks').returns(Promise.resolve({
                         settings: [{
                             value: '/:slug/'
                         }]
@@ -602,7 +602,7 @@ describe('Frontend Controller', function () {
 
             describe('permalink set to slug', function () {
                 beforeEach(function () {
-                    apiSettingsStub.withArgs('permalinks').returns(when({
+                    apiSettingsStub.withArgs('permalinks').returns(Promise.resolve({
                         settings: [{
                             value: '/:slug/'
                         }]
@@ -674,7 +674,7 @@ describe('Frontend Controller', function () {
 
             describe('permalink set to date', function () {
                 beforeEach(function () {
-                    apiSettingsStub.withArgs('permalinks').returns(when({
+                    apiSettingsStub.withArgs('permalinks').returns(Promise.resolve({
                         settings: [{
                             value: '/:year/:month/:day/:slug/'
                         }]
@@ -747,7 +747,7 @@ describe('Frontend Controller', function () {
         describe('post', function () {
             describe('permalink set to slug', function () {
                 beforeEach(function () {
-                    apiSettingsStub.withArgs('permalinks').returns(when({
+                    apiSettingsStub.withArgs('permalinks').returns(Promise.resolve({
                         settings: [{
                             value: '/:slug'
                         }]
@@ -821,7 +821,7 @@ describe('Frontend Controller', function () {
 
             describe('permalink set to date', function () {
                 beforeEach(function () {
-                    apiSettingsStub.withArgs('permalinks').returns(when({
+                    apiSettingsStub.withArgs('permalinks').returns(Promise.resolve({
                         settings: [{
                             value: '/:year/:month/:day/:slug'
                         }]
@@ -912,7 +912,7 @@ describe('Frontend Controller', function () {
 
             describe('permalink set to custom format', function () {
                 beforeEach(function () {
-                    apiSettingsStub.withArgs('permalinks').returns(when({
+                    apiSettingsStub.withArgs('permalinks').returns(Promise.resolve({
                         settings: [{
                             value: '/:year/:slug'
                         }]
@@ -1035,25 +1035,25 @@ describe('Frontend Controller', function () {
             };
 
             sandbox.stub(api.posts, 'browse', function () {
-                return when({posts: {}, meta: {pagination: { pages: 3}}});
+                return Promise.resolve({posts: {}, meta: {pagination: { pages: 3}}});
             });
 
-            apiUsersStub = sandbox.stub(api.users, 'read').returns(when({}));
+            apiUsersStub = sandbox.stub(api.users, 'read').returns(Promise.resolve({}));
 
             apiSettingsStub = sandbox.stub(api.settings, 'read');
-            apiSettingsStub.withArgs('title').returns(when({
+            apiSettingsStub.withArgs('title').returns(Promise.resolve({
                 settings: [{
                     'key': 'title',
                     'value': 'Test'
                 }]
             }));
-            apiSettingsStub.withArgs('description').returns(when({
+            apiSettingsStub.withArgs('description').returns(Promise.resolve({
                 settings: [{
                     'key': 'description',
                     'value': 'Some Text'
                 }]
             }));
-            apiSettingsStub.withArgs('permalinks').returns(when({
+            apiSettingsStub.withArgs('permalinks').returns(Promise.resolve({
                 settings: [{
                     'key': 'permalinks',
                     'value': '/:slug/'
diff --git a/core/test/unit/mail_spec.js b/core/test/unit/mail_spec.js
index c527fc3a42..890c93f55c 100644
--- a/core/test/unit/mail_spec.js
+++ b/core/test/unit/mail_spec.js
@@ -2,7 +2,7 @@
 /*jshint expr:true*/
 var should          = require('should'),
     sinon           = require('sinon'),
-    when            = require('when'),
+    Promise         = require('bluebird'),
     _               = require('lodash'),
     rewire          = require('rewire'),
 
@@ -61,7 +61,7 @@ describe('Mail', function () {
         });
 
         sandbox.stub(mailer, 'detectSendmail', function () {
-            return when.resolve(fakeSendmail);
+            return Promise.resolve(fakeSendmail);
         });
     });
 
@@ -119,7 +119,7 @@ describe('Mail', function () {
     it('should disable transport if config is empty & sendmail not found', function (done) {
         overrideConfig({mail: {}});
         mailer.detectSendmail.restore();
-        sandbox.stub(mailer, 'detectSendmail', when.reject);
+        sandbox.stub(mailer, 'detectSendmail', Promise.reject);
         mailer.init().then(function () {
             should.not.exist(mailer.transport);
             done();
@@ -141,7 +141,7 @@ describe('Mail', function () {
 
     it('should fail to send messages when no transport is set', function (done) {
         mailer.detectSendmail.restore();
-        sandbox.stub(mailer, 'detectSendmail', when.reject);
+        sandbox.stub(mailer, 'detectSendmail', Promise.reject);
         mailer.init().then(function () {
             mailer.send().then(function () {
                 should.fail();
@@ -154,15 +154,15 @@ describe('Mail', function () {
     });
 
     it('should fail to send messages when given insufficient data', function (done) {
-        when.settle([
+        Promise.settle([
             mailer.send(),
             mailer.send({}),
             mailer.send({ subject: '123' }),
             mailer.send({ subject: '', html: '123' })
         ]).then(function (descriptors) {
             descriptors.forEach(function (d) {
-                d.state.should.equal('rejected');
-                d.reason.should.be.an.instanceOf(Error);
+                d.isRejected().should.be.true;
+                d.reason().should.be.an.instanceOf(Error);
             });
             done();
         }).catch(done);
diff --git a/core/test/unit/permissions_spec.js b/core/test/unit/permissions_spec.js
index 25429a15c8..9da5700619 100644
--- a/core/test/unit/permissions_spec.js
+++ b/core/test/unit/permissions_spec.js
@@ -3,7 +3,7 @@
 var testUtils       = require('../utils'),
     should          = require('should'),
     sinon           = require('sinon'),
-    when            = require('when'),
+    Promise         = require('bluebird'),
     _               = require('lodash'),
 
     // Stuff we are testing
@@ -31,7 +31,7 @@ describe('Permissions', function () {
         });
 
         sandbox.stub(Models.Permission, 'findAll', function () {
-            return when(Models.Permissions.forge(permissions));
+            return Promise.resolve(Models.Permissions.forge(permissions));
         });
 
     });
@@ -112,7 +112,7 @@ describe('Permissions', function () {
 //    it('can use permissible function on Model to allow something', function (done) {
 //        var testUser,
 //            permissibleStub = sandbox.stub(Models.Post, 'permissible', function () {
-//                return when.resolve();
+//                return Promise.resolve();
 //            });
 //
 //        testUtils.insertAuthorUser()
@@ -141,7 +141,7 @@ describe('Permissions', function () {
 //    it('can use permissible function on Model to forbid something', function (done) {
 //        var testUser,
 //            permissibleStub = sandbox.stub(Models.Post, 'permissible', function () {
-//                return when.reject();
+//                return Promise.reject();
 //            });
 //
 //        testUtils.insertAuthorUser()
@@ -203,7 +203,7 @@ describe('Permissions', function () {
 //
 //                        return newPerm.save(null, context).then(function () {
 //                            return foundUser.permissions().attach(newPerm).then(function () {
-//                                return when.all([updatedPost, foundUser]);
+//                                return Promise.all([updatedPost, foundUser]);
 //                            });
 //                        });
 //                    });
diff --git a/core/test/unit/server_helpers_index_spec.js b/core/test/unit/server_helpers_index_spec.js
index 36b66d0fc4..b7877ce7d6 100644
--- a/core/test/unit/server_helpers_index_spec.js
+++ b/core/test/unit/server_helpers_index_spec.js
@@ -2,7 +2,7 @@
 /*jshint expr:true*/
 var should         = require('should'),
     sinon          = require('sinon'),
-    when           = require('when'),
+    Promise        = require('bluebird'),
     _              = require('lodash'),
     rewire         = require('rewire'),
     moment         = require('moment'),
@@ -30,7 +30,7 @@ describe('Core Helpers', function () {
         helpers = rewire('../../server/helpers');
         sandbox = sinon.sandbox.create();
         apiStub = sandbox.stub(api.settings, 'read', function () {
-            return when({
+            return Promise.resolve({
                 settings: [{value: 'casper'}]
             });
         });
@@ -393,7 +393,7 @@ describe('Core Helpers', function () {
         });
 
         it('can render class string for context', function (done) {
-            when.all([
+            Promise.all([
                 helpers.body_class.call({relativeUrl: '/'}),
                 helpers.body_class.call({relativeUrl: '/a-post-title', post: {}}),
                 helpers.body_class.call({relativeUrl: '/page/4'}),
@@ -762,7 +762,7 @@ describe('Core Helpers', function () {
         beforeEach(function () {
             apiStub.restore();
             apiStub = sandbox.stub(api.settings, 'read', function () {
-                return when({ settings: [{ value: '/:slug/' }] });
+                return Promise.resolve({ settings: [{ value: '/:slug/' }] });
             });
         });
 
diff --git a/core/test/unit/xmlrpc_spec.js b/core/test/unit/xmlrpc_spec.js
index 4abd3d2a49..6a2583657f 100644
--- a/core/test/unit/xmlrpc_spec.js
+++ b/core/test/unit/xmlrpc_spec.js
@@ -5,7 +5,7 @@ var nock            = require('nock'),
     should          = require('should'),
     sinon           = require('sinon'),
     testUtils       = require('../utils'),
-    when            = require('when'),
+    Promise         = require('bluebird'),
     xmlrpc          = require('../../server/xmlrpc'),
     // storing current environment
     currentEnv      = process.env.NODE_ENV;
@@ -34,7 +34,7 @@ describe('XMLRPC', function () {
             ping2 = nock('http://rpc.pingomatic.com').post('/').reply(200),
             testPost = testUtils.DataGenerator.Content.posts[2],
             settingsStub = sandbox.stub(settings, 'read', function () {
-                return when({ settings: [{value: '/:slug/'}] });
+                return Promise.resolve({ settings: [{value: '/:slug/'}] });
             });
         /*jshint unused:false */
 
diff --git a/core/test/utils/fork.js b/core/test/utils/fork.js
index 6113fe477c..ace95b935e 100644
--- a/core/test/utils/fork.js
+++ b/core/test/utils/fork.js
@@ -3,33 +3,39 @@ var cp         = require('child_process'),
     fs         = require('fs'),
     url        = require('url'),
     net        = require('net'),
-    when       = require('when'),
+    Promise    = require('bluebird'),
     path       = require('path'),
     config     = require('../../server/config');
     
 function findFreePort(port) {
-    var deferred = when.defer();
-
-    if (typeof port === 'string') port = parseInt(port);
-    if (typeof port !== 'number') port = 2368;
-    port = port + 1;
-
-    var server = net.createServer();
-    server.on('error', function(e) {
-        if (e.code === 'EADDRINUSE') {
-            when.chain(findFreePort(port), deferred);
-        } else {
-            deferred.reject(e);
+    return new Promise(function (resolve, reject) {
+        if (typeof port === 'string') {
+            port = parseInt(port);
         }
-    });
-    server.listen(port, function() {
-        var listenPort = server.address().port;
-        server.close(function() {
-            deferred.resolve(listenPort);
+
+        if (typeof port !== 'number') {
+            port = 2368;
+        }
+
+        port = port + 1;
+
+        var server = net.createServer();
+
+        server.on('error', function(e) {
+            if (e.code === 'EADDRINUSE') {
+                resolve(findFreePort(port));
+            } else {
+                reject(e);
+            }
+        });
+
+        server.listen(port, function() {
+            var listenPort = server.address().port;
+            server.close(function() {
+                resolve(listenPort);
+            });
         });
     });
-    
-    return deferred.promise;
 }
 
 // Get a copy of current config object from file, to be modified before
@@ -43,85 +49,87 @@ function forkConfig() {
 // Creates a new fork of Ghost process with a given config
 // Useful for tests that want to verify certain config options
 function forkGhost(newConfig, envName) {
-    var deferred = when.defer();
     envName = envName || 'forked';
-    findFreePort(newConfig.server ? newConfig.server.port : undefined)
+
+    return findFreePort(newConfig.server ? newConfig.server.port : undefined)
         .then(function(port) {
             newConfig.server = newConfig.server || {};
             newConfig.server.port = port;
             newConfig.url = url.format(_.extend(url.parse(newConfig.url), {port: port, host: null}));
-            
+
             var newConfigFile = path.join(config.paths.appRoot, 'config.test' + port + '.js');
-            fs.writeFile(newConfigFile, 'module.exports = {' + envName + ': ' + JSON.stringify(newConfig) + '}', function(err) {
-                if (err) throw err;
-                
-                // setup process environment for the forked Ghost to use the new config file
-                var env = _.clone(process.env);
-                env['GHOST_CONFIG'] = newConfigFile;
-                env['NODE_ENV'] = envName;
-                var child = cp.fork(path.join(config.paths.appRoot, 'index.js'), {env: env});
-                
-                var pingTries = 0;
-                var pingCheck;
-                var pingStop = function() {
-                    if (pingCheck) {
-                        clearInterval(pingCheck);
-                        pingCheck = undefined;
-                        return true;
+
+            return new Promise(function (resolve, reject) {
+                fs.writeFile(newConfigFile, 'module.exports = {' + envName + ': ' + JSON.stringify(newConfig) + '}', function(err) {
+                    if (err) {
+                        return reject(err);
                     }
-                    return false;
-                };
-                // periodic check until forked Ghost is running and is listening on the port
-                pingCheck = setInterval(function() {
-                    var socket = net.connect(port);
-                    socket.on('connect', function() {
-                        socket.end();
-                        if (pingStop()) {
-                            deferred.resolve(child);
+
+                    // setup process environment for the forked Ghost to use the new config file
+                    var env = _.clone(process.env);
+                    env['GHOST_CONFIG'] = newConfigFile;
+                    env['NODE_ENV'] = envName;
+                    var child = cp.fork(path.join(config.paths.appRoot, 'index.js'), {env: env});
+
+                    var pingTries = 0;
+                    var pingCheck;
+                    var pingStop = function() {
+                        if (pingCheck) {
+                            clearInterval(pingCheck);
+                            pingCheck = undefined;
+                            return true;
                         }
-                    });
-                    socket.on('error', function(err) {
-                        // continue checking
-                        if (++pingTries >= 20 && pingStop()) {
-                            deferred.reject(new Error("Timed out waiting for child process"));
-                        }
-                    });
-                }, 200);
-        
-                child.on('exit', function(code, signal) {
-                    child.exited = true;
-                    if (pingStop()) {
-                        deferred.reject(new Error("Child process exit code: " + code));
-                    }
-                    // cleanup the temporary config file
-                    fs.unlink(newConfigFile);
-                });
-                
-                // override kill() to have an async callback
-                var baseKill = child.kill;
-                child.kill = function(signal, cb) {
-                    if (typeof signal === 'function') {
-                        cb = signal;
-                        signal = undefined;
-                    }
-                    
-                    if (cb) {
-                        child.on('exit', function() {
-                            cb();
+                        return false;
+                    };
+                    // periodic check until forked Ghost is running and is listening on the port
+                    pingCheck = setInterval(function() {
+                        var socket = net.connect(port);
+                        socket.on('connect', function() {
+                            socket.end();
+                            if (pingStop()) {
+                                resolve(child);
+                            }
                         });
-                    }
+                        socket.on('error', function(err) {
+                            // continue checking
+                            if (++pingTries >= 20 && pingStop()) {
+                                reject(new Error("Timed out waiting for child process"));
+                            }
+                        });
+                    }, 200);
 
-                    if (child.exited) {
-                        process.nextTick(cb);
-                    } else {
-                        baseKill.apply(child, [signal]);
-                    }
-                };
+                    child.on('exit', function(code, signal) {
+                        child.exited = true;
+                        if (pingStop()) {
+                            reject(new Error("Child process exit code: " + code));
+                        }
+                        // cleanup the temporary config file
+                        fs.unlink(newConfigFile);
+                    });
+                    
+                    // override kill() to have an async callback
+                    var baseKill = child.kill;
+                    child.kill = function(signal, cb) {
+                        if (typeof signal === 'function') {
+                            cb = signal;
+                            signal = undefined;
+                        }
+
+                        if (cb) {
+                            child.on('exit', function() {
+                                cb();
+                            });
+                        }
+
+                        if (child.exited) {
+                            process.nextTick(cb);
+                        } else {
+                            baseKill.apply(child, [signal]);
+                        }
+                    };
+                });
             });
-        })
-        .otherwise(deferred.reject);
-
-    return deferred.promise;
+        });
 }
 
 module.exports.ghost = forkGhost;
diff --git a/core/test/utils/index.js b/core/test/utils/index.js
index f819b8adb7..24801709df 100644
--- a/core/test/utils/index.js
+++ b/core/test/utils/index.js
@@ -1,6 +1,5 @@
-var when          = require('when'),
-    sequence      = require('when/sequence'),
-    nodefn        = require('when/node'),
+var Promise       = require('bluebird'),
+    sequence      = require('../../server/utils/sequence'),
     _             = require('lodash'),
     fs            = require('fs-extra'),
     path          = require('path'),
@@ -32,7 +31,7 @@ var when          = require('when'),
 fixtures = {
     insertPosts: function insertPosts() {
         var knex = config.database.knex;
-        return when(knex('posts').insert(DataGenerator.forKnex.posts)).then(function () {
+        return Promise.resolve(knex('posts').insert(DataGenerator.forKnex.posts)).then(function () {
             return knex('tags').insert(DataGenerator.forKnex.tags);
         }).then(function () {
             return knex('posts_tags').insert(DataGenerator.forKnex.posts_tags);
@@ -49,7 +48,7 @@ fixtures = {
 
         max = max || 50;
         // insert users of different roles
-        return when(fixtures.createUsersWithRoles()).then(function (results) {
+        return Promise.resolve(fixtures.createUsersWithRoles()).then(function (results) {
             // create the tags
             return knex('tags').insert(DataGenerator.forKnex.tags);
         }).then(function (results) {
@@ -72,7 +71,7 @@ fixtures = {
                 };
             }));
         }).then(function () {
-            return when.all([
+            return Promise.all([
                 // PostgreSQL can return results in any order
                 knex('posts').orderBy('id', 'asc').select('id'),
                 knex('tags').select('id')
@@ -84,7 +83,7 @@ fixtures = {
                 i;
 
             if (max > posts.length) {
-                throw new Error('Trying to add more posts_tags than the number of posts.');
+                throw new Error('Trying to add more posts_tags than the number of posts. ' + max + ' ' + posts.length);
             }
 
             for (i = 0; i < max; i += 1) {
@@ -133,7 +132,7 @@ fixtures = {
 
         var knex = config.database.knex;
 
-        return when.all([
+        return Promise.all([
             // PostgreSQL can return results in any order
             knex('posts').orderBy('id', 'asc').select('id'),
             knex('tags').select('id', 'name')
@@ -268,16 +267,17 @@ fixtures = {
     },
 
     loadExportFixture: function loadExportFixture(filename) {
-        var filepath = path.resolve(__dirname + '/fixtures/' + filename + '.json');
+        var filepath = path.resolve(__dirname + '/fixtures/' + filename + '.json'),
+            readFile = Promise.promisify(fs.readFile);
 
-        return nodefn.call(fs.readFile, filepath).then(function (fileContents) {
+        return readFile(filepath).then(function (fileContents) {
             var data;
 
             // Parse the json data
             try {
                 data = JSON.parse(fileContents);
             } catch (e) {
-                return when.reject(new Error('Failed to parse the file'));
+                return new Error('Failed to parse the file');
             }
 
             return data;
@@ -451,7 +451,6 @@ setup = function setup() {
 // TODO make this do the DB init as well
 doAuth = function doAuth() {
     var options = arguments,
-        deferred = when.defer(),
         request = arguments[0],
         user = DataGenerator.forModel.users[0],
         fixtureOps;
@@ -466,19 +465,19 @@ doAuth = function doAuth() {
 
     fixtureOps = getFixtureOps(options);
 
-    sequence(fixtureOps).then(function () {
-        request.post('/ghost/api/v0.1/authentication/token/')
-            .send({ grant_type: 'password', username: user.email, password: user.password, client_id: 'ghost-admin'})
-            .end(function (err, res) {
-                if (err) {
-                    deferred.reject(err);
-                }
+    return new Promise(function (resolve, reject) {
+        return sequence(fixtureOps).then(function () {
+            request.post('/ghost/api/v0.1/authentication/token/')
+                .send({ grant_type: 'password', username: user.email, password: user.password, client_id: 'ghost-admin'})
+                .end(function (err, res) {
+                    if (err) {
+                        return reject(err);
+                    }
 
-                deferred.resolve(res.body.access_token);
-            });
+                    resolve(res.body.access_token);
+                });
+        });
     });
-
-    return deferred.promise;
 };
 
 teardown = function teardown(done) {
diff --git a/package.json b/package.json
index 6a8f42ed32..bf2da2ccc2 100644
--- a/package.json
+++ b/package.json
@@ -32,6 +32,7 @@
     "engineStrict": true,
     "dependencies": {
         "bcryptjs": "0.7.10",
+        "bluebird": "2.3.0",
         "body-parser": "1.6.3",
         "bookshelf": "0.7.6",
         "busboy": "0.2.3",
@@ -63,7 +64,6 @@
         "static-favicon": "1.0.2",
         "unidecode": "0.1.3",
         "validator": "3.4.0",
-        "when": "3.2.3",
         "xml": "0.0.12"
     },
     "optionalDependencies": {