If you are counting MBs at that order, then wxWidgets would be the best option. It can be statically linked easily. The size overhead is about 2.5-3 MB. It is a

If you are counting MBs at that order, then wxWidgets would be the best option. It can be statically linked easily. The size overhead is about 2.5-3 MB. It is a thin wrapper on top of native controls, so e.g. you can always get to the underlying HWND on Windows. Even for the Windows only app, I'd still pick it due to the sane API.