AssaultCube

AssaultCube, formerly ActionCube, is a free first-person-shooter based on the game Cube. It is set in a realistic-looking environment, as far as that's possible with this engine, while gameplay stays fast and arcade-like. This game is all about team-oriented multiplayer fun.

Thanks to the efficient networking code, AssaultCube requires very little bandwidth: you can play it with a 56k modem Internet connection, and AssaultCube runs on old hardware.

Create new maps (virtual worlds) together with other people online. The cooperative edit mode makes it possible.

Like its origin, Cube, AssaultCube comes with full source code, available under a zlib-like Open Source license. Because AssaultCube uses the SDL library, it can be used on multiple platforms.