Red eclipse is an open source multi-platform fps game (windows, mac, linux). Red Eclipse offers a wide variety of Quake style weapons and maps but with it’s own unique twist. All weapons have a secondary fire that applies to different situations and there are plenty of maps to choose from. On top of which the game has jetpacks and a variety of acrobatic tricks you can perform like wall walking.
This is a great game from any lan party – it’s is easy to pick up and fun to play, and can run at very low settings if need be for older machines.