Mingw-w64 is an advancement of the original mingw.org project, created to support the GCC compiler on Windows systems. It has forked it in 2007 in order to provide support for 64 bits and new APIs. It has since then gained widespread use and distribution.
The development and community are very active and welcoming with new contributors every month and simple installers.
You can also look at the full list of versions.
Mingw-w64 interacts a lot with other projects in order to help everyone move forward. Contributions have been going to and coming from these projects:
Crash if compiled with -flto, -static and iostream is used
winerror.h: Added DWRITE_E_* defines.
wincodec.idl: Added GUID_WICPixelFormat* GUIDs.
math: Preserve NAN/INF in rint(f) on ARM
math: Fix rounding in ceilf and floorf on ARM
math: Fix rounding in llrintl on ARM
math: Make sure NAN/INF are preserved in floor/...
Change check for _WIN64 to check for __x86_64__...
Implement IAMAsyncReaderTimestampScaling and IA...
Avoid declaring something extern AND initializi...