diff --git a/AK/Assertions.h b/AK/Assertions.h
index f78ccd921b2..ca074781f18 100644
--- a/AK/Assertions.h
+++ b/AK/Assertions.h
@@ -1,13 +1,16 @@
 #pragma once
 
+#ifdef SERENITY_KERNEL
+#include "kassert.h"
+#else
 #include <assert.h>
-
 #define ASSERT(x) assert(x)
 #define ASSERT_NOT_REACHED() assert(false)
+#endif
 
 namespace AK {
 
-inline void notImplemented() { assert(false); }
+inline void notImplemented() { ASSERT(false); }
 
 }
 
diff --git a/AK/MappedFile.cpp b/AK/MappedFile.cpp
index 0afec761855..6a8ad3515b4 100644
--- a/AK/MappedFile.cpp
+++ b/AK/MappedFile.cpp
@@ -22,7 +22,7 @@ MappedFile::MappedFile(String&& fileName)
             perror("");
     }
 
-    printf("MappedFile{%s} := { m_fd=%d, m_fileLength=%u, m_map=%p }\n", m_fileName.characters(), m_fd, m_fileLength, m_map);
+    printf("MappedFile{%s} := { m_fd=%d, m_fileLength=%zu, m_map=%p }\n", m_fileName.characters(), m_fd, m_fileLength, m_map);
 }
 
 MappedFile::~MappedFile()
diff --git a/AK/Retainable.h b/AK/Retainable.h
index 1d22428e901..cf4308520c3 100644
--- a/AK/Retainable.h
+++ b/AK/Retainable.h
@@ -15,7 +15,7 @@ public:
 
     void release()
     {
-        assert(m_retainCount);
+        ASSERT(m_retainCount);
         if (!--m_retainCount)
             delete static_cast<const T*>(this);
     }
diff --git a/AK/SimpleMalloc.cpp b/AK/SimpleMalloc.cpp
index ef8c8483af1..e92d7295d0a 100644
--- a/AK/SimpleMalloc.cpp
+++ b/AK/SimpleMalloc.cpp
@@ -222,6 +222,8 @@ byte* allocateZeroed(dword size)
 byte* reallocate(byte* ptr, dword size)
 {
     // FIXME;
+    (void) ptr;
+    (void) size;
     ASSERT_NOT_REACHED();
     return nullptr;
 }
diff --git a/AK/StdLib.h b/AK/StdLib.h
index c4448ed4235..a5046e530f7 100644
--- a/AK/StdLib.h
+++ b/AK/StdLib.h
@@ -1,5 +1,12 @@
 #pragma once
 
+#ifdef SERENITY_KERNEL
+#include <Kernel/StdLib.h>
+#else
+#include <cstring>
+#include <utility>
+#endif
+
 namespace AK {
 
 template<typename T>
@@ -34,10 +41,10 @@ template<typename T>
 struct identity {
     typedef T type;
 };
-template<typename T>
-T&& forward(typename identity<T>::type&& param)
+template<class T>
+constexpr T&& forward(typename identity<T>::type& param)
 {
-    return static_cast<typename identity<T>::type&&>(param);
+    return static_cast<T&&>(param);
 }
 
 template<typename T, typename U>
diff --git a/AK/Types.h b/AK/Types.h
index f970c128481..38cd7cb9256 100644
--- a/AK/Types.h
+++ b/AK/Types.h
@@ -1,10 +1,18 @@
 #pragma once
 
 #ifdef SERENITY_KERNEL
+typedef unsigned char byte;
+typedef unsigned short word;
+typedef unsigned int dword;
+typedef unsigned long long int qword;
+
+typedef signed char signed_byte;
+typedef signed short signed_word;
+typedef signed int signed_dword;
+typedef signed long long int signed_qword;
 #else
 #include <stdint.h>
 #include <sys/types.h>
-#endif
 
 typedef uint8_t byte;
 typedef uint16_t word;
@@ -15,6 +23,7 @@ typedef int8_t signed_byte;
 typedef int16_t signed_word;
 typedef int32_t signed_dword;
 typedef int64_t signed_qword;
+#endif
 
 constexpr unsigned KB = 1024;
 constexpr unsigned MB = KB * KB;
diff --git a/AK/Vector.h b/AK/Vector.h
index 3bf78213675..971e45f192e 100644
--- a/AK/Vector.h
+++ b/AK/Vector.h
@@ -13,24 +13,24 @@ template<typename T>
 class VectorImpl {
 public:
     ~VectorImpl() { }
-    static OwnPtr<VectorImpl> create(unsigned capacity)
+    static OwnPtr<VectorImpl> create(size_t capacity)
     {
         size_t size = sizeof(VectorImpl) + sizeof(T) * capacity;
         void* slot = kmalloc(size);
         return OwnPtr<VectorImpl>(new (slot) VectorImpl(capacity));
     }
 
-    unsigned size() const { return m_size; }
-    unsigned capacity() const { return m_capacity; }
+    size_t size() const { return m_size; }
+    size_t capacity() const { return m_capacity; }
 
-    T& at(unsigned i) { return *slot(i); }
-    const T& at(unsigned i) const { return *slot(i); }
+    T& at(size_t i) { return *slot(i); }
+    const T& at(size_t i) const { return *slot(i); }
 
-    void remove(unsigned index)
+    void remove(size_t index)
     {
         ASSERT(index < m_size);
         at(index).~T();
-        for (unsigned i = index + 1; i < m_size; ++i) {
+        for (size_t i = index + 1; i < m_size; ++i) {
             new (slot(i - 1)) T(move(at(i)));
             at(i).~T();
         }
@@ -41,16 +41,16 @@ public:
 private:
     friend class Vector<T>;
 
-    VectorImpl(unsigned capacity) : m_capacity(capacity) { }
+    VectorImpl(size_t capacity) : m_capacity(capacity) { }
 
     T* tail() { return reinterpret_cast<T*>(this + 1); }
-    T* slot(unsigned i) { return &tail()[i]; }
+    T* slot(size_t i) { return &tail()[i]; }
 
     const T* tail() const { return reinterpret_cast<const T*>(this + 1); }
-    const T* slot(unsigned i) const { return &tail()[i]; }
+    const T* slot(size_t i) const { return &tail()[i]; }
 
-    unsigned m_size { 0 };
-    unsigned m_capacity;
+    size_t m_size { 0 };
+    size_t m_capacity;
 };
 
 template<typename T>
@@ -73,21 +73,21 @@ public:
 
     void clear()
     {
-        for (unsigned i = 0; i < size(); ++i) {
+        for (size_t i = 0; i < size(); ++i) {
             at(i).~T();
         }
         m_impl = nullptr;
     }
 
     bool isEmpty() const { return size() == 0; }
-    unsigned size() const { return m_impl ? m_impl->size() : 0; }
-    unsigned capacity() const { return m_impl ? m_impl->capacity() : 0; }
+    size_t size() const { return m_impl ? m_impl->size() : 0; }
+    size_t capacity() const { return m_impl ? m_impl->capacity() : 0; }
 
-    const T& at(unsigned i) const { return m_impl->at(i); }
-    T& at(unsigned i) { return m_impl->at(i); }
+    const T& at(size_t i) const { return m_impl->at(i); }
+    T& at(size_t i) { return m_impl->at(i); }
 
-    const T& operator[](unsigned i) const { return at(i); }
-    T& operator[](unsigned i) { return at(i); }
+    const T& operator[](size_t i) const { return at(i); }
+    T& operator[](size_t i) { return at(i); }
 
     const T& first() const { return at(0); }
     T& first() { return at(0); }
@@ -104,7 +104,7 @@ public:
         return value;
     }
 
-    void remove(unsigned index)
+    void remove(size_t index)
     {
         m_impl->remove(index);
     }
@@ -123,7 +123,7 @@ public:
         ++m_impl->m_size;
     }
 
-    void ensureCapacity(unsigned neededCapacity)
+    void ensureCapacity(size_t neededCapacity)
     {
         if (capacity() >= neededCapacity)
             return;
@@ -131,7 +131,7 @@ public:
         auto newImpl = VectorImpl<T>::create(newCapacity);
         if (m_impl) {
             newImpl->m_size = m_impl->m_size;
-            for (unsigned i = 0; i < size(); ++i) {
+            for (size_t i = 0; i < size(); ++i) {
                 new (newImpl->slot(i)) T(move(m_impl->at(i)));
                 m_impl->at(i).~T();
             }
@@ -146,9 +146,9 @@ public:
         T& operator*() { return m_vector[m_index]; }
     private:
         friend class Vector;
-        Iterator(Vector& vector, unsigned index) : m_vector(vector), m_index(index) { }
+        Iterator(Vector& vector, size_t index) : m_vector(vector), m_index(index) { }
         Vector& m_vector;
-        unsigned m_index { 0 };
+        size_t m_index { 0 };
     };
 
     Iterator begin() { return Iterator(*this, 0); }
@@ -161,18 +161,18 @@ public:
         const T& operator*() const { return m_vector[m_index]; }
     private:
         friend class Vector;
-        ConstIterator(const Vector& vector, const unsigned index) : m_vector(vector), m_index(index) { }
+        ConstIterator(const Vector& vector, const size_t index) : m_vector(vector), m_index(index) { }
         const Vector& m_vector;
-        unsigned m_index { 0 };
+        size_t m_index { 0 };
     };
 
     ConstIterator begin() const { return ConstIterator(*this, 0); }
     ConstIterator end() const { return ConstIterator(*this, size()); }
 
 private:
-    static unsigned paddedCapacity(unsigned capacity)
+    static size_t paddedCapacity(size_t capacity)
     {
-        return max(4u, capacity + (capacity / 4) + 4);
+        return max(size_t(4), capacity + (capacity / 4) + 4);
     }
 
     OwnPtr<VectorImpl<T>> m_impl;
diff --git a/AK/kmalloc.cpp b/AK/kmalloc.cpp
index deeacc7a673..5540bfa0911 100644
--- a/AK/kmalloc.cpp
+++ b/AK/kmalloc.cpp
@@ -9,12 +9,12 @@
 
 extern "C" {
 
-void* kcalloc(dword nmemb, dword size)
+void* kcalloc(size_t nmemb, size_t size)
 {
     return calloc(nmemb, size);
 }
 
-void* kmalloc(dword size)
+void* kmalloc(size_t size)
 {
     return malloc(size);
 }
@@ -24,7 +24,7 @@ void kfree(void* ptr)
     free(ptr);
 }
 
-void* krealloc(void* ptr, dword size)
+void* krealloc(void* ptr, size_t size)
 {
     return realloc(ptr, size);
 }
@@ -35,14 +35,14 @@ void* krealloc(void* ptr, dword size)
 
 extern "C" {
 
-void* kcalloc(dword nmemb, dword size)
+void* kcalloc(size_t nmemb, size_t size)
 {
     if (!nmemb || !size)
         return nullptr;
     return SimpleMalloc::allocateZeroed(nmemb * size);
 }
 
-void* kmalloc(dword size)
+void* kmalloc(size_t size)
 {
     if (!size)
         return nullptr;
@@ -56,7 +56,7 @@ void kfree(void* ptr)
     SimpleMalloc::free((byte*)ptr);
 }
 
-void* krealloc(void* ptr, dword size)
+void* krealloc(void* ptr, size_t size)
 {
     if (!ptr)
         return ptr;
diff --git a/AK/kmalloc.h b/AK/kmalloc.h
index 89b455bb70e..2c30774456b 100644
--- a/AK/kmalloc.h
+++ b/AK/kmalloc.h
@@ -4,10 +4,10 @@
 
 extern "C" {
 
-void* kcalloc(dword nmemb, dword size);
-void* kmalloc(dword size);
+void* kcalloc(size_t nmemb, size_t size);
+void* kmalloc(size_t size);
 void kfree(void* ptr);
-void* krealloc(void* ptr, dword size);
+void* krealloc(void* ptr, size_t size);
 
 }
 
diff --git a/AK/test.cpp b/AK/test.cpp
index 92838cbc290..0cb2b89de7f 100644
--- a/AK/test.cpp
+++ b/AK/test.cpp
@@ -136,7 +136,7 @@ int main(int, char**)
     }
 
     auto charbuf = Buffer<char>::createUninitialized(1024);
-    printf("charbuf.size() = %u\n", charbuf->size());
+    printf("charbuf.size() = %zu\n", charbuf->size());
 
     {
     Vector<String> problem;
@@ -146,7 +146,7 @@ int main(int, char**)
 
     {
         auto printInts = [] (const Vector<int>& v) {
-            printf("Vector {\n    size: %u\n    capacity: %u\n    elements: ", v.size(), v.capacity());
+            printf("Vector {\n    size: %zu\n    capacity: %zu\n    elements: ", v.size(), v.capacity());
             for (auto i : v)
                 printf("%d ", i);
             printf("\n}\n");