diff --git a/.vscode/c_cpp_properties.json b/.vscode/c_cpp_properties.json
index f4f13cf..5375bbf 100644
--- a/.vscode/c_cpp_properties.json
+++ b/.vscode/c_cpp_properties.json
@@ -10,6 +10,7 @@
                 "UNICODE",
                 "_UNICODE",
                 "GEN_TIME",
+                "Build_Debug",
             ],
             "windowsSdkVersion": "10.0.22621.0",
             "compilerPath": "cl.exe",
diff --git a/HandmadeHero.10x b/HandmadeHero.10x
index 610cfe0..6bdde83 100644
--- a/HandmadeHero.10x
+++ b/HandmadeHero.10x
@@ -38,6 +38,8 @@
 			<AdditionalIncludePath>C:\Program Files (x86)\Windows Kits\NETFXSDK\4.8\include\um</AdditionalIncludePath>
 		</AdditionalIncludePaths>
 		<Defines>
+			<Define>UNICODE</Define>
+			<Define>_UNICODE</Define>
 			<Define>GEN_TIME</Define>
 		</Defines>
 		<ConfigProperties>
diff --git a/handmade-hero-notes b/handmade-hero-notes
index 0a6995a..6b43c05 160000
--- a/handmade-hero-notes
+++ b/handmade-hero-notes
@@ -1 +1 @@
-Subproject commit 0a6995a2cb6217d01b463bb4416c5d30c075333b
+Subproject commit 6b43c05d4800c498eb3c9b24e976f9a7eddf3301
diff --git a/project/handmade_win32.cpp b/project/handmade_win32.cpp
index 8b25d37..a08e7db 100644
--- a/project/handmade_win32.cpp
+++ b/project/handmade_win32.cpp
@@ -1,13 +1,172 @@
-#include "win32.h"
+#if __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-const-variable"
+#pragma clang diagnostic ignored "-Wswitch"
+#pragma clang diagnostic ignored "-Wunused-variable"
+#pragma clang diagnostic ignored "-Wunknown-pragmas"
+#pragma clang diagnostic ignored "-Wvarargs"
+#pragma clang diagnostic ignored "-Wunused-function"
+#endif
 
-int CALLBACK WinMain(
-	HINSTANCE hInstance,
-	HINSTANCE hPrevInstance,
-	LPSTR     lpCmdLine,
-	int       nShowCmd
+#include "grime.h"
+#include "macros.h"
+#include "types.h"
+
+#include "win32.h"
+// using namespace win32;
+
+// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nc-winuser-wndproc
+// https://learn.microsoft.com/en-us/windows/win32/winmsg/about-messages-and-message-queues#system-defined-messages
+LRESULT CALLBACK MainWindowCallback(
+	HWND   handle,
+	UINT   system_messages,
+	WPARAM w_param,
+	LPARAM l_param
 )
 {
-	MessageBox( 0, L"First message!", L"Handmade Hero", MB_OK | MB_ICONINFORMATION );
+	LRESULT result;
+
+	// https://learn.microsoft.com/en-us/windows/win32/winmsg/window-notifications
+	switch ( system_messages )
+	{
+		case WM_ACTIVATEAPP:
+		{
+			OutputDebugStringA( "WM_ACTIVATEAPP\n" );
+		}
+		break;
+
+		case WM_CLOSE:
+		{
+			OutputDebugStringA( "WM_CLOSE\n" );
+		}
+		break;
+
+		case WM_DESTROY:
+		{
+			OutputDebugStringA( "WM_DESTROY\n" );
+		}
+		break;
+
+		case WM_PAINT:
+		{
+			PAINTSTRUCT info;
+			HDC device_context = BeginPaint( handle, & info );
+
+			u32 x 	   = info.rcPaint.left;
+			u32 y 	   = info.rcPaint.top;
+			u32 height = info.rcPaint.bottom - info.rcPaint.top;
+			u32 width  = info.rcPaint.right  - info.rcPaint.left;
+
+			global DWORD operation = RO_Whiteness;
+
+			PatBlt( device_context
+				, x, y
+				, width, height
+				, operation );
+
+			operation == RO_Whiteness ?
+				operation = RO_Blackness
+			:	operation = RO_Whiteness;
+
+			EndPaint( handle, & info );
+		}
+		break;
+
+		case WM_SIZE:
+		{
+			OutputDebugStringA( "WM_SIZE\n" );
+		}
+		break;
+
+		default:
+		{
+			OutputDebugStringA( "default\n" );
+			result = DefWindowProc( handle, system_messages, w_param, l_param );
+		}
+	}
+
+	return result;
+}
+
+int CALLBACK WinMain(
+	HINSTANCE instance,
+	HINSTANCE prev_instance,
+	LPSTR     commandline,
+	int       show_command
+)
+{
+	// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-messagebox
+	// MessageBox( 0, L"First message!", L"Handmade Hero", MB_Ok_Btn | MB_Icon_Information );
+
+	// https://en.wikibooks.org/wiki/Windows_Programming/Window_Creation
+	// https://learn.microsoft.com/en-us/windows/win32/api/winuser/ns-winuser-wndclassa
+	WNDCLASS window_class {};
+		// window_class.style = CS_OWNDC | CS_HREDRAW | CS_VREDRAW;
+		window_class.style = CS_Own_Device_Context | CS_Horizontal_Redraw | CS_Vertical_Redraw;
+		window_class.lpfnWndProc = MainWindowCallback;
+		// window_class.cbClsExtra  = ;
+		// window_class.cbWndExtra  = ;
+		window_class.hInstance   = instance;
+		// window_class.hIcon = ;
+		// window_class.hCursor = ;
+		// window_class.hbrBackground = ;
+		window_class.lpszMenuName  = L"Handmade Hero!";
+		window_class.lpszClassName = L"HandmadeHeroWindowClass";
+
+	if ( RegisterClassW( &window_class ) )
+	{
+		// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-createwindowexa
+		// https://learn.microsoft.com/en-us/windows/win32/winmsg/window-styles
+		HWND window_handle = CreateWindowExW(
+			0,
+			window_class.lpszClassName,
+			L"Handmade Hero",
+			// WS_OVERLAPPEDWINDOW | WS_VISIBLE,
+			WS_Overlapped_Window | WS_Initially_Visible,
+			CW_USEDEFAULT, CW_USEDEFAULT, // x, y
+			CW_USEDEFAULT, CW_USEDEFAULT, // width, height
+			0, 0,                         // parent, menu
+			instance, 0                   // instance, param
+		);
+
+		if ( window_handle )
+		{
+			// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-showwindow
+			// ShowWindow( window_handle, show_command );
+
+			// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-updatewindow
+			// UpdateWindow( window_handle );
+
+			// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getmessage
+			MSG message;
+			for (;;)
+			{
+				BOOL msg_result = GetMessage( & message, 0, 0, 0 );
+				if ( msg_result > 0 )
+				{
+					// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-translatemessage
+					TranslateMessage( & message );
+
+					// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-dispatchmessage
+					DispatchMessage( & message );
+					// break;
+				}
+				else
+				{
+					// TODO (Ed) : Logging
+					break;
+				}
+			}
+		}
+		else
+		{
+			// TODO (Ed) : Logging
+		}
+	}
+	else
+	{
+		// TODO(Ed) : Logging
+	}
 
 	return 0;
 }
diff --git a/project/platform/grime.h b/project/platform/grime.h
new file mode 100644
index 0000000..77f1c17
--- /dev/null
+++ b/project/platform/grime.h
@@ -0,0 +1,111 @@
+#pragma region Platform Detection
+
+/* Platform architecture */
+
+#if defined( _WIN64 ) || defined( __x86_64__ ) || defined( _M_X64 ) || defined( __64BIT__ ) || defined( __powerpc64__ ) || defined( __ppc64__ ) || defined( __aarch64__ )
+#	ifndef GEN_ARCH_64_BIT
+#		define GEN_ARCH_64_BIT 1
+#	endif
+#else
+#	ifndef GEN_ARCH_32_BItxt_StrCaT
+#		define GEN_ARCH_32_BIT 1
+#	endif
+#endif
+
+/* Platform OS */
+
+#if defined( _WIN32 ) || defined( _WIN64 )
+#	ifndef GEN_SYSTEM_WINDOWS
+#		define GEN_SYSTEM_WINDOWS 1
+#	endif
+#elif defined( __APPLE__ ) && defined( __MACH__ )
+#	ifndef GEN_SYSTEM_OSX
+#		define GEN_SYSTEM_OSX 1
+#	endif
+#	ifndef GEN_SYSTEM_MACOS
+#		define GEN_SYSTEM_MACOS 1
+#	endif
+#	include <TargetConditionals.h>
+#	if TARGET_IPHONE_SIMULATOR == 1 || TARGET_OS_IPHONE == 1
+#		ifndef GEN_SYSTEM_IOS
+#			define GEN_SYSTEM_IOS 1
+#		endif
+#	endif
+#elif defined( __unix__ )
+#	ifndef GEN_SYSTEM_UNIX
+#		define GEN_SYSTEM_UNIX 1
+#	endif
+#	if defined( ANDROID ) || defined( __ANDROID__ )
+#		ifndef GEN_SYSTEM_ANDROID
+#			define GEN_SYSTEM_ANDROID 1
+#		endif
+#		ifndef GEN_SYSTEM_LINUX
+#			define GEN_SYSTEM_LINUX 1
+#		endif
+#	elif defined( __linux__ )
+#		ifndef GEN_SYSTEM_LINUX
+#			define GEN_SYSTEM_LINUX 1
+#		endif
+#	elif defined( __FreeBSD__ ) || defined( __FreeBSD_kernel__ )
+#		ifndef GEN_SYSTEM_FREEBSD
+#			define GEN_SYSTEM_FREEBSD 1
+#		endif
+#	elif defined( __OpenBSD__ )
+#		ifndef GEN_SYSTEM_OPENBSD
+#			define GEN_SYSTEM_OPENBSD 1
+#		endif
+#	elif defined( __EMSCRIPTEN__ )
+#		ifndef GEN_SYSTEM_EMSCRIPTEN
+#			define GEN_SYSTEM_EMSCRIPTEN 1
+#		endif
+#	elif defined( __CYGWIN__ )
+#		ifndef GEN_SYSTEM_CYGWIN
+#			define GEN_SYSTEM_CYGWIN 1
+#		endif
+#	else
+#		error This UNIX operating system is not supported
+#	endif
+#else
+#	error This operating system is not supported
+#endif
+
+/* Platform compiler */
+
+#if defined( _MSC_VER )
+#	define GEN_COMPILER_MSVC 1
+#elif defined( __GNUC__ )
+#	define GEN_COMPILER_GCC 1
+#elif defined( __clang__ )
+#	define GEN_COMPILER_CLANG 1
+#elif defined( __MINGW32__ )
+#	define GEN_COMPILER_MINGW 1
+#	error Unknown compiler
+#endif
+
+#if defined( __has_attribute )
+#	define GEN_HAS_ATTRIBUTE( attribute ) __has_attribute( attribute )
+#else
+#	define GEN_HAS_ATTRIBUTE( attribute ) ( 0 )
+#endif
+
+#if defined(GEN_GCC_VERSION_CHECK)
+#  undef GEN_GCC_VERSION_CHECK
+#endif
+#if defined(GEN_GCC_VERSION)
+#  define GEN_GCC_VERSION_CHECK(major,minor,patch) (GEN_GCC_VERSION >= GEN_VERSION_ENCODE(major, minor, patch))
+#else
+#  define GEN_GCC_VERSION_CHECK(major,minor,patch) (0)
+#endif
+
+#pragma endregion Platform Detection
+
+#pragma region Mandatory Includes
+
+#	include <stdarg.h>
+#	include <stddef.h>
+
+#	if defined( GEN_SYSTEM_WINDOWS )
+#		include <intrin.h>
+#	endif
+
+#pragma endregion Mandatory Includes
diff --git a/project/platform/macros.h b/project/platform/macros.h
new file mode 100644
index 0000000..faace17
--- /dev/null
+++ b/project/platform/macros.h
@@ -0,0 +1,5 @@
+// Keywords
+
+#define global        static    // Global variables
+#define internal      static    // Internal linkage
+#define local_persist static    // Local Persisting variables
diff --git a/project/platform/types.h b/project/platform/types.h
new file mode 100644
index 0000000..693db15
--- /dev/null
+++ b/project/platform/types.h
@@ -0,0 +1,120 @@
+#pragma region Basic Types
+
+#define U8_MIN 0u
+#define U8_MAX 0xffu
+#define I8_MIN ( -0x7f - 1 )
+#define I8_MAX 0x7f
+
+#define U16_MIN 0u
+#define U16_MAX 0xffffu
+#define I16_MIN ( -0x7fff - 1 )
+#define I16_MAX 0x7fff
+
+#define U32_MIN 0u
+#define U32_MAX 0xffffffffu
+#define I32_MIN ( -0x7fffffff - 1 )
+#define I32_MAX 0x7fffffff
+
+#define U64_MIN 0ull
+#define U64_MAX 0xffffffffffffffffull
+#define I64_MIN ( -0x7fffffffffffffffll - 1 )
+#define I64_MAX 0x7fffffffffffffffll
+
+#if defined( GEN_ARCH_32_BIT )
+#	define USIZE_MIN GEN_U32_MIN
+#	define USIZE_MAX GEN_U32_MAX
+#	define ISIZE_MIN GEN_S32_MIN
+#	define ISIZE_MAX GEN_S32_MAX
+#elif defined( GEN_ARCH_64_BIT )
+#	define USIZE_MIN GEN_U64_MIN
+#	define USIZE_MAX GEN_U64_MAX
+#	define ISIZE_MIN GEN_I64_MIN
+#	define ISIZE_MAX GEN_I64_MAX
+#else
+#	error Unknown architecture size. This library only supports 32 bit and 64 bit architectures.
+#endif
+
+#define F32_MIN 1.17549435e-38f
+#define F32_MAX 3.40282347e+38f
+#define F64_MIN 2.2250738585072014e-308
+#define F64_MAX 1.7976931348623157e+308
+
+#if defined( GEN_COMPILER_MSVC )
+#	if _MSC_VER < 1300
+typedef unsigned char  u8;
+typedef signed   char  s8;
+typedef unsigned short u16;
+typedef signed   short s16;
+typedef unsigned int   u32;
+typedef signed   int   s32;
+#    else
+typedef unsigned __int8  u8;
+typedef signed   __int8  s8;
+typedef unsigned __int16 u16;
+typedef signed   __int16 s16;
+typedef unsigned __int32 u32;
+typedef signed   __int32 s32;
+#    endif
+typedef unsigned __int64 u64;
+typedef signed   __int64 s64;
+#else
+#	include <stdint.h>
+
+typedef uint8_t  u8;
+typedef int8_t   s8;
+typedef uint16_t u16;
+typedef int16_t  s16;
+typedef uint32_t u32;
+typedef int32_t  s32;
+typedef uint64_t u64;
+typedef int64_t  s64;
+#endif
+
+static_assert( sizeof( u8 )  == sizeof( s8 ),  "sizeof(u8) != sizeof(s8)" );
+static_assert( sizeof( u16 ) == sizeof( s16 ), "sizeof(u16) != sizeof(s16)" );
+static_assert( sizeof( u32 ) == sizeof( s32 ), "sizeof(u32) != sizeof(s32)" );
+static_assert( sizeof( u64 ) == sizeof( s64 ), "sizeof(u64) != sizeof(s64)" );
+
+static_assert( sizeof( u8 )  == 1, "sizeof(u8) != 1" );
+static_assert( sizeof( u16 ) == 2, "sizeof(u16) != 2" );
+static_assert( sizeof( u32 ) == 4, "sizeof(u32) != 4" );
+static_assert( sizeof( u64 ) == 8, "sizeof(u64) != 8" );
+
+typedef size_t    uw;
+typedef ptrdiff_t sw;
+
+static_assert( sizeof( uw ) == sizeof( sw ), "sizeof(uw) != sizeof(sw)" );
+
+// NOTE: (u)zpl_intptr is only here for semantic reasons really as this library will only support 32/64 bit OSes.
+#if defined( _WIN64 )
+typedef signed   __int64 sptr;
+typedef unsigned __int64 uptr;
+#elif defined( _WIN32 )
+// NOTE; To mark types changing their size, e.g. zpl_intptr
+#	ifndef _W64
+#		if ! defined( __midl ) && ( defined( _X86_ ) || defined( _M_IX86 ) ) && _MSC_VER >= 1300
+#			define _W64 __w64
+#		else
+#			define _W64
+#		endif
+#	endif
+typedef _W64 signed int   sptr;
+typedef _W64 unsigned int uptr;
+#else
+typedef uintptr_t uptr;
+typedef intptr_t  sptr;
+#endif
+
+static_assert( sizeof( uptr ) == sizeof( sptr ), "sizeof(uptr) != sizeof(sptr)" );
+
+typedef float  f32;
+typedef double f64;
+
+static_assert( sizeof( f32 ) == 4, "sizeof(f32) != 4" );
+static_assert( sizeof( f64 ) == 8, "sizeof(f64) != 8" );
+
+typedef s8  b8;
+typedef s16 b16;
+typedef s32 b32;
+
+#pragma endregion Basic Types
diff --git a/project/platform/win32.h b/project/platform/win32.h
index e4c48d3..064a8e5 100644
--- a/project/platform/win32.h
+++ b/project/platform/win32.h
@@ -5,8 +5,121 @@ Alternative header for windows.h
 #include "windows/windows_base.h"
 #include "windows/window.h"
 
-#ifdef UNICODE
-constexpr auto MessageBox = MessageBoxW;
+// #ifdef Build_Debug
+#	include "windows/dbghelp.h"
+// #endif
+
+#if Build_DLL
+#	define WIN_LIBRARY_API extern "C" __declspec(dllexport)
 #else
-constexpr auto MessageBox = MessageBoxA;
+#	define WIN_LIBRARY_API extern "C"
+#endif
+
+#ifndef CONST
+#	define CONST const
+#endif
+
+#define WM_ACTIVATEAPP 0x001C
+
+
+// namespace win32 {
+
+#ifdef UNICODE
+	constexpr auto CreateWindowEx = CreateWindowExW;
+#else
+	constexpr auto CreateWindowEx = CreateWindowExA;
 #endif // !UNICODE
+
+#ifdef UNICODE
+	constexpr auto DefWindowProc = DefWindowProcW;
+#else
+	constexpr auto DefWindowProc = DefWindowProcA;
+#endif // !UNICODE
+
+#ifdef UNICODE
+	constexpr auto DispatchMessage = DispatchMessageW;
+#else
+	constexpr auto DispatchMessage = DispatchMessageA;
+#endif // !UNICODE
+
+#pragma region Message Function Templates
+// From WinUser.h, modular headers lib doesn't have.
+
+WIN_LIBRARY_API BOOL WINAPI GetMessageA(
+    LPMSG lpMsg,
+    HWND hWnd,
+    UINT wMsgFilterMin,
+    UINT wMsgFilterMax);
+WIN_LIBRARY_API BOOL WINAPI GetMessageW(
+    LPMSG lpMsg,
+    HWND hWnd,
+    UINT wMsgFilterMin,
+    UINT wMsgFilterMax);
+#ifdef UNICODE
+	constexpr auto GetMessage = GetMessageW;
+#else
+	constexpr auto GetMessage = GetMessageA;
+#endif // !UNICODE
+
+#ifdef UNICODE
+	constexpr auto MessageBox = MessageBoxW;
+#else
+	constexpr auto MessageBox = MessageBoxA;
+#endif // !UNICODE
+
+#ifdef UNICODE
+	constexpr auto RegisterClass = RegisterClassW;
+#else
+	constexpr auto RegisterClass = RegisterClassA;
+#endif // !UNICODE
+#pragma endregion Message Function Templates
+
+#pragma region Window PAINT
+typedef struct tagPAINTSTRUCT {
+    HDC         hdc;
+    BOOL        fErase;
+    RECT        rcPaint;
+    BOOL        fRestore;
+    BOOL        fIncUpdate;
+    BYTE        rgbReserved[32];
+} PAINTSTRUCT, *PPAINTSTRUCT, *NPPAINTSTRUCT, *LPPAINTSTRUCT;
+
+WIN_LIBRARY_API HDC WINAPI
+BeginPaint( HWND hWnd, LPPAINTSTRUCT lpPaint );
+
+WIN_LIBRARY_API BOOL WINAPI
+EndPaint( HWND hWnd, CONST PAINTSTRUCT *lpPaint );
+
+WIN_LIBRARY_API BOOL WINAPI PatBlt( HDC hdc, int x, int y, int w, int h, DWORD rop );
+#pragma endregion Window PAINT
+
+// Class Style Constants
+// https://learn.microsoft.com/en-us/windows/win32/winmsg/about-window-classes
+// https://learn.microsoft.com/en-us/windows/win32/winmsg/window-class-styles
+
+enum CS : UINT
+{
+	CS_Own_Device_Context = CS_OWNDC,
+	CS_Horizontal_Redraw  = CS_HREDRAW,
+	CS_Vertical_Redraw    = CS_VREDRAW,
+};
+
+enum MB : UINT
+{
+	MB_Ok_Btn = MB_OK,
+	MB_Icon_Information = MB_ICONINFORMATION,
+};
+
+enum WS : UINT
+{
+	WS_Overlapped_Window = WS_OVERLAPPEDWINDOW,
+	WS_Initially_Visible = WS_VISIBLE,
+};
+
+enum RasterOps : DWORD
+{
+	RO_Blackness = (DWORD)0x00000042,
+	RO_Whiteness = (DWORD)0x00FF0062,
+};
+
+// }
diff --git a/scripts/build.ps1 b/scripts/build.ps1
index d67f04a..9e13bf0 100644
--- a/scripts/build.ps1
+++ b/scripts/build.ps1
@@ -319,23 +319,26 @@ $linker_args = @(
 )
 
 #region Handmade Generate
-$unit       = Join-Path $path_gen   'handmade_gen.cpp'
-$executable = Join-Path $path_build 'handmade_gen.exe'
-
-build-simple $includes $compiler_args $linker_args $unit $executable
-write-host
-
-& $executable
-write-host
-
 if ( $false ) {
-	Remove-Item (Get-ChildItem -Path $path_build -Recurse -Force)
+	$unit       = Join-Path $path_gen   'handmade_gen.cpp'
+	$executable = Join-Path $path_build 'handmade_gen.exe'
+
+	build-simple $includes $compiler_args $linker_args $unit $executable
+	write-host
+
+	& $executable
+	write-host
+
+	if ( $false ) {
+		Remove-Item (Get-ChildItem -Path $path_build -Recurse -Force)
+	}
 }
 #endregion Handmade Generate
 
 #region Handmade Runtime
 
 $lib_user32 = 'User32.lib'
+$lib_gdi32  = 'Gdi32.lib'
 
 $unit       = Join-Path $path_project 'handmade_win32.cpp'
 $executable = Join-Path $path_build   'handmade_win32.exe'
@@ -343,6 +346,7 @@ $executable = Join-Path $path_build   'handmade_win32.exe'
 $compiler_args = @()
 
 $linker_args = @(
+	$lib_gdi32,
 	$lib_user32,
 	$flag_link_win_subsystem_windows
 )