Xonotic – free first-person shooter
Xonotic is a free fast-paced first-person shooter that works on Windows, OS X and Linux.Xonotic is a direct successor of the Nexuiz project. The game is based off the Darkplaces game engine which is originally a quake modification. Xonotic has incredibly good graphics for an opensource game and is on par with most commercial games from 2006-2007. The gameplay is of course slightly inspired by several other games, but it is essentially a unique mixture of mostly original and different ideas.