Phoronix: New 3D Game Engine Targets Linux Gamers

While there are many open-source games available (just see the recent discussion about the most advanced GPL-ed FPS), most of them are based upon the ioquake3 game engine that in turn is based upon id Software's open-source id Tech 3 engine. There's also games like Nexuiz that use the DarkPlaces engine and then also Warsow that uses QFusion...

http://www.phoronix.com/vr.php?view=Nzk4Mg