MinGW: A native Windows port of the GNU Compiler Collection (GCC), with freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All of MinGW's software will execute on the 64bit Windows platforms.
MinGW.org Binary Utilities (GNU binutils)
GNU Liberty Library (32-bit) ex. GNU binutils Version 2.28-1