Warzone 2100 is a real-time strategy and real-time tactics hybrid computer game, developed by Pumpkin Studios and published by Eidos Interactive. It was originally released in 1999 for Microsoft Windows and PlayStation. On December 6, 2004 the source code and most of its data was released under the GNU General Public License. On June 10, 2008, the license was clarified and loosened to permit distribution of the films and soundtrack.
It has since been developed, maintained, and improved by the "Warzone 2100 Project". Proprietary technologies were replaced with open alternatives (ex: OpenGL, OpenAL), and the game now supports Windows, macOS, Linux, and even FreeBSD.