Port of GNU tool to windows.
TDM-GCC is a compiler suite for Windows. It combines the most recent stable release of the GCC toolset, a few patches for Windows-friendliness, and the free and open-source MinGW
Bundle installer for the TDM32 MinGW edition. Includes C, C++, and OpenMP support, SJLJ exception handling, other GNU toolchain programs (binutils), Windows API libraries (MinGW WSL), GNU make (mingw32-make), and the GNU debugger (GDB).
http://tdm-gcc.tdragon.net/download (Make, gcc, …)
http://gnuwin32.sourceforge.net/
GnuWin provides ports of tools with a GNU or similar open source license, to modern MS-Windows (Microsoft Windows 2000 / XP / 2003 / Vista / 2008 / 7)