DJGPP is a non-proprietary environment for developing 32-bit protected mode software in C and C++ under MS-DOS. It contains a port of GCC as well as plenty of other GNU software such as Bash and GNU Emacs. The DJGPP home page on the WWW is http://www.delorie.com/djgpp/
Status and other information (online docs, FAQ, mail archives) are made available through the DJGPP web pages. Discussion of DJGPP and questions about its usage or features are through the djgpp newsgroup (post to comp.os.msdos.djgpp) and djgpp mailing list (send your messages to djgpp@delorie.com, subscribe through listserv@delorie.com). Look on the web page for information on the latest versions of various DJGPP packages.
DJGPP is available on your local Simtel.net mirror, in the directory /pub/simtelnet/gnu/djgpp/v2* . There are hundreds of packages; the Zip Picker script on the DJGPP web site can help you decide which ones to download.
Source: DJGPP web site http://www.delorie.com/djgpp/
The DJGPP system was used to create several popular games such as Quake, many Doom source mods, Tetanus On Drugs, nearly all DOS-based Allegro library games, and the DOS versions of several console emulators such as SNES9x.