Assault Cube is a free Creative Commons licensed first person shooter game. It’s multi-platform (Mac, Linux and Windoze), very small and can be played multi-player over a 56k dial-up modem. You can even run it on an ancient Pentium 3 machine. Nice to see someone thinking of the cave-dwellers amongst us, eh?
AssaultCube, formerly ActionCube, is a free first-person-shooter based on the game Cube. Set in a realistic looking environment, as far as that´s possible with this engine, while gameplay stays fast and arcade. This game is all about team oriented multiplayer fun.