The last time I built a native Windows app years ago, I used WTL 3.0. It’s a light weight wrapper on the native Win32 API, lighter than MFC. It took out the unpleasantness of working directly on Win32 API and wrapped it in a simple OO framework. It had access to all features of Win32. It could produce runtime binary in dozens of K, instead of MB or GB.

Microsoft released it open source later on. Looking at the repository, looks like it has been kept up and maintained, up to version 10 now.

GitHub mirror of the sourceforge repo: https://github.com/Win32-WTL/WTL

WTL delivers very small and efficient code, very close in size and speed to SDK programs, while presenting a more logical, object oriented model to a programmer.