Quick Answer: Mingw-w64 is a free and open source software development environment to create Microsoft Windows applications. It was forked in 2005-2008 from MinGW. Mingw-w64 includes a port of the GNU Compiler Collection, GNU Binutils for Windows, a set of freely distributable Windows specific header files and static import libraries which enable the use of the Windows API, a Windows native build of the GNU Project's GNU Debugger, and miscellaneous utilities. Mingw-w64 can be run either on the native Microsoft Windows platform, cross-hosted on Linux, or "cross-native" on MSYS2 or Cygwin. Mingw-w64 can generate 32 and 64 bits executables.