diff --git a/src/base/base_entry_point.c b/src/base/base_entry_point.c
index 68d3440..84bb0a7 100644
--- a/src/base/base_entry_point.c
+++ b/src/base/base_entry_point.c
@@ -1 +1,7 @@
-internal void main_thread_entry_point(void) { ThreadNameF("[main thread]"); }
+internal void main_thread_entry_point(void) {
+  ThreadNameF("[main thread]");
+
+#if defined(OS_GFX_H)
+  os_gfx_init();
+#endif
+}
diff --git a/src/goff/goff.c b/src/goff/goff.c
new file mode 100644
index 0000000..f0c5e37
--- /dev/null
+++ b/src/goff/goff.c
@@ -0,0 +1,20 @@
+internal void update_and_render(OS_Handle repaint_window_handle) {
+  Temp scratch = scratch_begin(0, 0);
+
+  // pick target hz
+  f32 target_hz = os_get_gfx_info()->default_referesh_rate;
+
+  // Target HZ -> delta time
+  f32 dt = 1.f / target_hz;
+
+  // Get events from OS
+  OS_EventList events = {0};
+  if (os_handle_match(repaint_window_handle, os_handle_zero())) {
+    events = os_get_events(scratch.arena, df_gfx_state->num_frames_requested == 0);
+  }
+
+  // begin frames
+  {
+    df_core_begin(scratch.arena,
+  }
+}
diff --git a/src/goff/goff.h b/src/goff/goff.h
new file mode 100644
index 0000000..a905b21
--- /dev/null
+++ b/src/goff/goff.h
@@ -0,0 +1,6 @@
+#ifndef GOFF_H
+#define GOFF_H
+
+internal void update_and_render(OS_HANDLE repaint_window);
+
+#endif // GOFF_H
diff --git a/src/goff/goff_main.c b/src/goff/goff_main.c
index b85c0a8..f5dd6ed 100644
--- a/src/goff/goff_main.c
+++ b/src/goff/goff_main.c
@@ -10,4 +10,28 @@
 
 // clang-format on
 
-u64 main(int argc, char **argv) { return 0; }
+// Entry Point
+
+internal void entry_point() {
+  Temp scratch = scratch_begin(0, 0);
+
+  // Setup layers
+  // {
+  //   df_core_init();
+  //   df_gfx_init();
+}
+
+// Main application loop
+{
+  for (;;) {
+
+    // Update and render frame here
+    OS_Handle repaint_window = {0};
+    update_and_render(repaint_window);
+
+    // Quit
+  }
+}
+
+scratch_end(scratch);
+}
diff --git a/src/os/core/os_core.h b/src/os/core/os_core.h
index 9690d4f..5d35c2f 100644
--- a/src/os/core/os_core.h
+++ b/src/os/core/os_core.h
@@ -11,6 +11,12 @@ struct OS_SystemInfo {
   String8 machine_name;
 };
 
+// Handle types
+typedef struct OS_Handle OS_Handle;
+struct OS_Handle {
+  u64 l_u64[1];
+}
+
 // Process Information
 typedef struct OS_ProcessInfo OS_ProcessInfo;
 struct OS_ProcessInfo {
diff --git a/src/os/gfx/os_gfx.h b/src/os/gfx/os_gfx.h
new file mode 100644
index 0000000..3c80983
--- /dev/null
+++ b/src/os/gfx/os_gfx.h
@@ -0,0 +1,33 @@
+#ifndefine OS_GFX_H
+#define OS_GFX_H
+
+typedef void OS_WindowRepaintFunctionType(OS_Handle window, void *user_data);
+
+ty
+
+typedef struct OS_Event OS_Event;
+struct OS_Event {
+  OS_Event *next;
+  OS_Event *previous;
+  u64 timestamp_us;
+  OS_Handle window;
+  OS_EventKind kind;
+  OS_EventFlag flags;
+  OS_Key key;
+  b32 is_repeat;
+  b32 right_sided;
+  u32 character;
+  u32 repeat_count;
+  Vec2F32 position;
+  Vec2F32 delta;
+  String8List strings;
+};
+
+typedef struct OS_EventList OS_EventList;
+struct OS_EventList {
+  u64 count;
+  OS_Event *first;
+  OS_Event *last;
+};
+
+#endif // OS_GFX_H
diff --git a/src/os/gfx/win32/os_gfx_win32.c b/src/os/gfx/win32/os_gfx_win32.c
new file mode 100644
index 0000000..3beaef4
--- /dev/null
+++ b/src/os/gfx/win32/os_gfx_win32.c
@@ -0,0 +1,4 @@
+internal void os_gfx_init(void) {
+  Arena *arena = arena_alloc();
+  os_w32_gfx_state =
+}
diff --git a/src/os/gfx/win32/os_gfx_win32.h b/src/os/gfx/win32/os_gfx_win32.h
new file mode 100644
index 0000000..9158298
--- /dev/null
+++ b/src/os/gfx/win32/os_gfx_win32.h
@@ -0,0 +1,51 @@
+#ifndef OS_GFX_WIN32_H
+#define OS_GFX_WIN32_H
+
+// Windows
+typedef struct OS_W32_Window OS_W32_Window;
+struct OS_W32_Window {
+  OS_W32_Window                *next;
+  OS_W32_Window                *prev;
+  HWND                         *hwnd;
+  WINDOWPLACEMENT               last_window_placement;
+  OS_WindowRepaintFunctionType *repaint;
+  void                         *repaint_user_data;
+  f32                           dpi;
+  b32                           first_paint_done;
+  b32                           maximized;
+  Arena                        *pain_arena;
+};
+
+// Global State
+typedef struct OS_W32_GfxState OS_W32_GfxState;
+struct OS_W32_GfxState {
+  Arena         *arena;
+  u32            gfx_thread_id;
+  HINSTANCE      hInstance;
+  HCURSOR        hCursor;
+  OS_GfxInfo     gfx_info;
+  OS_W32_Window *first_window;
+  OS_W32_Window *last_window;
+  OS_W32_Window *free_window;
+  OS_KEY         key_from_vkey_table[256];
+};
+
+// Globals
+global OS_W32_GfxState *os_w32_gfx_state   = 0;
+global OS_EventList     os_w32_event_list  = {0};
+global Arena           *os_w32_event_arena = 0;
+b32                     os_w32_resizing    = 0;
+
+// Windows
+internal OS_Handle      os_w32_handle_from_window(OS_W32_Window *window);
+internal OS_W32_Window *os_w32_window_from_handle(OS_Handle window);
+internal OS_W32_Window *os_w32_window_from_hwnd(HWND hwnd);
+internal HWND           os_w32_hwnd_from_window(OS_W32_Window *window);
+internal OS_W32_Window *os_w32_window_alloc(void);
+internal void           os_w32_window_release(OS_W32_Window *window);
+internal OS_Event      *os_w32_push_event(OS_EventKind kind, OS_W32_Window *window);
+internal OS_Key         os_w32_os_key_from_vkey(WPARAM vkey);
+internal WPARAM         os_w32_vkey_from_os_key(OS_Key key);
+internal LRESULT        os_w32_wnd_proc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
+
+#endif // OS_GFX_WIN32_H