Valve Releases Updated Alien Swarm For Free With Code Base
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.
I don't really get how they can release UT engine games like that for free... don't they have to pay licensing fees to distribute the executable (like, not just a mod that requires UT2004)?
Tremulous uses 2k4 code too, and doesn't require UT2004, and it's free.