baronvoncarson tips news that today Valve released an updated version of Alien Swarm, a popular Unreal Tournament 2004 total conversion mod. The creators of the mod were hired by Valve, and they've helped turn it into a stand-alone game running on the Source engine. Valve is also releasing the code base for Alien Swarm and an SDK. The game is available for free on Steam.
Crusader writes "Black Cat Games has announced the release of Alien Swarm, their Unreal Tournament 2004 modification that features an overhead POV cooperative multiplayer battle against AI-driven aliens. There's torrents for both the trailer and the mod itself. Linux users are catered to as well: the ZIP package contains a shell script-based installer."