https://osdn.net/projects/mingw/
MinGW is another set of development tools that produce native Windows executables, not dependent on Cygwin’s POSIX emulation DLLs.
MSYS is a POSIX shell and minimal set of tools that are commonly used in configure scripts. Like Cygwin, this environment uses a non-native filesystem mapping to appear more POSIX like to the scripts that it runs. This is intended to complement the MinGW tools to make it easier to port software to Windows.