The Warzone 2100 Resurrection Project offers the free release of Warzone 2100, Pumpkin Studios' 20th century strategy game that's now GPL OpenSource as a result of the efforts of a group of dedicated fans, who have updated the game with OpenGL support and other nifty modern features. Mirrors of the full game for Windows, Linux, and Mac as well as a patch for owners of the original game are on FileFront and Gamer's Hell.