The following is a set of guidelines for contributing to Atom and its packages, which are hosted in the [Atom Organization](https://github.com/atom) on GitHub.
These are just guidelines, not rules, use your best judgment and feel free to propose changes to this document in a pull request.
When you initially consider contributing to Atom, you might be unsure about which of those 200 repositories implements the functionality you want to change or report a bug for.
This section should help you with that.
Atom is intentionally very modular.
Nearly every non-editor UI element you interact with comes from a package, even fundamental things like tabs and the status-bar.
These packages are packages in the same way that packages in the [package store](https://atom.io/packages) are packages, with one difference: they are bundled into the [default distribution](https://github.com/atom/atom/blob/10b8de6fc499a7def9b072739486e68530d67ab4/package.json#L58).
To get a sense for the packages that are bundled with Atom, you can go to Settings > Packages within Atom and take a look at the Core Packages section.
Here's a list of the big ones:
* [atom/atom](https://github.com/atom/atom) - Atom Core! The core editor component is responsible for basic text editing (e.g. cursors, selections, scrolling), text indentation, wrapping, and folding, text rendering, editor rendering, file system operations (e.g. saving), and installation and auto-updating. You should also use this repository for feedback related to the [core API](https://atom.io/docs/api/latest/Notification) and for large, overarching design proposals.
* [tree-view](https://github.com/atom/tree-view) - file and directory listing on the left of the UI.
* [find-and-replace](https://github.com/atom/find-and-replace) - all search and replace functionality.
* [tabs](https://github.com/atom/tabs) - the tabs for open editors at the top of the UI.
* [status-bar](https://github.com/atom/status-bar) - the status bar at the bottom of the UI.
* [markdown-preview](https://github.com/atom/markdown-preview) - the rendered markdown pane item.
* [settings-view](https://github.com/atom/settings-view) - the settings UI pane item.
* [autocomplete-plus](https://github.com/atom/autocomplete-plus) - autocompletions shown while typing. Some languages have additional packages for autocompletion functionality, such as [autocomplete-html](https://github.com/atom/autocomplete-html).
* [git-diff](https://github.com/atom/git-diff) - Git change indicators shown in the editor's gutter.
* [language-javascript](https://github.com/atom/language-javascript) - all bundled languages are packages too, and each one has a separate package `language-[name]`. Use these for feedback on syntax highlighting issues that only appear for a specific language.
* [one-dark-ui](https://github.com/atom/one-dark-ui) - the default UI styling for anything but the text editor. UI theme packages (i.e. packages with a `-ui` suffix) provide only styling and it's possible that a bundled package is responsible for a UI issue. There are other other bundled UI themes, such as [one-light-ui](https://github.com/atom/one-light-ui).
* [one-dark-syntax](https://github.com/atom/one-dark-syntax) - the default syntax highlighting styles applied for all languages. There are other other bundled syntax themes, such as [solarized-dark](https://github.com/atom/solarized-dark). You should use these packages for reporting issues that appear in many languages, but disappear if you change to another syntax theme.
* [apm](https://github.com/atom/apm) - the `apm` command line tool (Atom Package Manager). You should use this repository for any contributions related to the `apm` tool and to publishing packages.
* [atom.io](https://github.com/atom/atom.io) - the repository for feedback on the [Atom.io website](https://atom.io) and the [Atom.io package API](https://github.com/atom/atom/blob/master/docs/apm-rest-api.md) used by [apm](https://github.com/atom/apm).
There are many more, but this list should be a good starting point.
For more information on how to work with Atom's official packages, see [Contributing to Atom Packages](https://github.com/atom/atom/blob/master/docs/contributing-to-packages.md).
Also, because Atom is so extensible, it's possible that a feature you've become accustomed to in Atom or an issue you're encountering aren't coming from a bundled package at all, but rather a [community package](https://atom.io/packages) you've installed.
Each community package has its own repository too, and you should be able to find it in Settings > Packages for the packages you installed and contribute there.
Unsure where to begin contributing to Atom? You can start by looking through these `beginner` and `help-wanted` issues:
* [Beginner issues][beginner] - issues which should only require a few lines of code, and a test or two.
* [Help wanted issues][help-wanted] - issues which should be a bit more involved than `beginner` issues.
Both issue lists are sorted by total number of comments. While not perfect, number of comments is a reasonable proxy for impact a given change will have.
This section lists the labels we use to help us track and manage issues and pull requests. Most labels are used across all Atom repositories, but some are specific to `atom/atom`.
[GitHub search](https://help.github.com/articles/searching-issues/) makes it easy to use labels for finding groups of issues or pull requests you're interested in. For example, you might be interested in [open issues across `atom/atom` and all Atom-owned packages which are labeled as bugs, but still need to be reliably reproduced](https://github.com/issues?utf8=%E2%9C%93&q=is%3Aopen+is%3Aissue+user%3Aatom+label%3Abug+label%3Aneeds-reproduction) or perhaps [open pull requests in `atom/atom` which haven't been reviewed yet](https://github.com/issues?utf8=%E2%9C%93&q=is%3Aopen+is%3Apr+repo%3Aatom%2Fatom+comments%3A0). To help you find issues and pull requests, each label is listed with search links for finding open items with that label in `atom/atom` only and also across all Atom repositories. We encourage you to read about [other search filters](https://help.github.com/articles/searching-issues/) which will help you write more focused queries.
The labels are loosely grouped by their purpose, but it's not required that every issue have a label from every group or that an issue can't have more than one label from the same group.
Please open an issue on `atom/atom` if you have suggestions for new labels, and if you notice some labels are missing on some repositories, then please open an issue on that repository.
| `bug` | [search][search-atom-repo-label-bug] | [search][search-atom-org-label-bug] | Confirmed bugs or reports that are very likely to be bugs. |
| `question` | [search][search-atom-repo-label-question] | [search][search-atom-org-label-question] | Questions more than bug reports or feature requests (e.g. how do I do X). |
| `feedback` | [search][search-atom-repo-label-feedback] | [search][search-atom-org-label-feedback] | General feedback more than bug reports or feature requests. |
| `help-wanted` | [search][search-atom-repo-label-help-wanted] | [search][search-atom-org-label-help-wanted] | The Atom core team would appreciate help from the community in resolving these issues. |
| `beginner` | [search][search-atom-repo-label-beginner] | [search][search-atom-org-label-beginner] | Less complex issues which would be good first issues to work on for users who want to contribute to Atom. |
| `more-information-needed` | [search][search-atom-repo-label-more-information-needed] | [search][search-atom-org-label-more-information-needed] | More information needs to be collected about these problems or feature requests (e.g. steps to reproduce). |
| `needs-reproduction` | [search][search-atom-repo-label-needs-reproduction] | [search][search-atom-org-label-needs-reproduction] | Likely bugs, but haven't been reliably reproduced. |
| `blocked` | [search][search-atom-repo-label-blocked] | [search][search-atom-org-label-blocked] | Issues blocked on other issues. |
| `duplicate` | [search][search-atom-repo-label-duplicate] | [search][search-atom-org-label-duplicate] | Issues which are duplicates of other issues, i.e. they have been reported before. |
| `wontfix` | [search][search-atom-repo-label-wontfix] | [search][search-atom-org-label-wontfix] | The Atom core team has decided not to fix these issues for now, either because they're working as intended or for some other reason. |
| `invalid` | [search][search-atom-repo-label-invalid] | [search][search-atom-org-label-invalid] | Issues which are't valid (e.g. user errors). |
| `package-idea` | [search][search-atom-repo-label-package-idea] | [search][search-atom-org-label-package-idea] | Feature request which might be good candidates for new packages, instead of extending Atom or core Atom packages. |
| `wrong-repo` | [search][search-atom-repo-label-wrong-repo] | [search][search-atom-org-label-wrong-repo] | Issues reported on the wrong repository (e.g. a bug related to the [Settings View package](https://github.com/atom/settings-view) was reported on [Atom core](https://github.com/atom/atom)). |
| `windows` | [search][search-atom-repo-label-windows] | [search][search-atom-org-label-windows] | Related to Atom running on Windows. |
| `linux` | [search][search-atom-repo-label-linux] | [search][search-atom-org-label-linux] | Related to Atom running on Linux. |
| `mac` | [search][search-atom-repo-label-mac] | [search][search-atom-org-label-mac] | Related to Atom running on OSX. |
| `documentation` | [search][search-atom-repo-label-documentation] | [search][search-atom-org-label-documentation] | Related to any type of documentation (e.g. [API documentation](https://atom.io/docs/api/latest/Atom) and the [flight manual](https://atom.io/docs/latest/)). |
| `performance` | [search][search-atom-repo-label-performance] | [search][search-atom-org-label-performance] | Related to performance. |
| `security` | [search][search-atom-repo-label-security] | [search][search-atom-org-label-security] | Related to security. |
| `ui` | [search][search-atom-repo-label-ui] | [search][search-atom-org-label-ui] | Related to visual design. |
| `api` | [search][search-atom-repo-label-api] | [search][search-atom-org-label-api] | Related to Atom's public APIs. |
| `uncaught-exception` | [search][search-atom-repo-label-uncaught-exception] | [search][search-atom-org-label-uncaught-exception] | Issues about uncaught exceptions, normally created from the [Notifications package](https://github.com/atom/notifications). |
| `crash` | [search][search-atom-repo-label-crash] | [search][search-atom-org-label-crash] | Reports of Atom completely crashing. |
| `auto-indent` | [search][search-atom-repo-label-auto-indent] | [search][search-atom-org-label-auto-indent] | Related to auto-indenting text. |
| `encoding` | [search][search-atom-repo-label-encoding] | [search][search-atom-org-label-encoding] | Related to character encoding. |
| `network` | [search][search-atom-repo-label-network] | [search][search-atom-org-label-network] | Related to network problems or working with remote files (e.g. on network drives). |
| `git` | [search][search-atom-repo-label-git] | [search][search-atom-org-label-git] | Related to Git functionality (e.g. problems with gitignore files or with showing the correct file status). |
| `editor-rendering` | [search][search-atom-repo-label-editor-rendering] | [search][search-atom-org-label-editor-rendering] | Related to language-independent aspects of rendering text (e.g. scrolling, soft wrap, and font rendering). |
| `build-error` | [search][search-atom-repo-label-build-error] | [search][search-atom-org-label-build-error] | Related to problems with building Atom from source. |
| `error-from-pathwatcher` | [search][search-atom-repo-label-error-from-pathwatcher] | [search][search-atom-org-label-error-from-pathwatcher] | Related to errors thrown by the [pathwatcher library](https://github.com/atom/node-pathwatcher). |
| `error-from-save` | [search][search-atom-repo-label-error-from-save] | [search][search-atom-org-label-error-from-save] | Related to errors thrown when saving files. |
| `error-from-open` | [search][search-atom-repo-label-error-from-open] | [search][search-atom-org-label-error-from-open] | Related to errors thrown when opening files. |
| `installer` | [search][search-atom-repo-label-installer] | [search][search-atom-org-label-installer] | Related to the Atom installers for different OSes. |
| `auto-updater` | [search][search-atom-repo-label-auto-updater] | [search][search-atom-org-label-auto-updater] | Related to the auto-updater for different OSes. |
| `deprecation-help` | [search][search-atom-repo-label-deprecation-help] | [search][search-atom-org-label-deprecation-help] | Issues for helping package authors remove usage of deprecated APIs in packages. |
| `electron` | [search][search-atom-repo-label-electron] | [search][search-atom-org-label-electron] | Issues that require changes to [Electron](https://electron.atom.io) to fix or implement. |
| `in-progress` | [search][search-atom-repo-label-in-progress] | [search][search-atom-org-label-in-progress] | Tasks which the Atom core team is working on currently. |
| `on-deck` | [search][search-atom-repo-label-on-deck] | [search][search-atom-org-label-on-deck] | Tasks which the Atom core team plans to work on next. |
| `shipping` | [search][search-atom-repo-label-shipping] | [search][search-atom-org-label-shipping] | Tasks which the Atom core team completed and will be released in one of the next releases. |
| `post-1.0-roadmap` | [search][search-atom-repo-label-post-1.0-roadmap] | [search][search-atom-org-label-post-1.0-roadmap] | The Atom core team's roadmap post version 1.0.0. |
| `atom` | [search][search-atom-repo-label-atom] | [search][search-atom-org-label-atom] | Topics discussed for prioritization at the next meeting of Atom core team members. |
| `work-in-progress` | [search][search-atom-repo-label-work-in-progress] | [search][search-atom-org-label-work-in-progress] | Pull requests which are still being worked on, more changes will follow. |
| `needs-review` | [search][search-atom-repo-label-needs-review] | [search][search-atom-org-label-needs-review] | Pull requests which need code review, and approval from maintainers or Atom core team. |
| `under-review` | [search][search-atom-repo-label-under-review] | [search][search-atom-org-label-under-review] | Pull requests being reviewed by maintainers or Atom core team. |
| `requires-changes` | [search][search-atom-repo-label-requires-changes] | [search][search-atom-org-label-requires-changes] | Pull requests which need to be updated based on review comments and then reviewed again. |
| `needs-testing` | [search][search-atom-repo-label-needs-testing] | [search][search-atom-org-label-needs-testing] | Pull requests which need manual testing. |