Source, the engine that runs many of the games I love is having its software development kit go free. Makes me want to code games all over again!
How this might link into Steam is a mystery, though. I suppose you have to go through a process to get achievements onto the Steam platform.
Comments
Actually, I think I might layoff. From the RPS commenters:
And from Gabe Newell...
I looked at source a while back and it's C++ easy if you know how but intimidating to the untrained
then again UDK/UE3 isn't exactly a walk in the park coding requires knowledge of polymorphism and object oriented code techniques but with it's drop and drag systems (karma or something like that) you can do a lot without touching unrealscript