Making Team Fortress 2 free to play last week has had... unforeseen consequences. As Rock, Paper, Shotgun reports, the change set in motion a series of events that will lead Valve to release its Source Engine software development toolkit (SDK) free of charge.
RPS points to this Reddit thread, which says a mod playtester by the name of Riley asked Valve if grabbing the free version of TF2 and buying an item from the Mann Co. store would grant him access to the Source SDK. Valve's Robin Walker reportedly shot back, "Yep. That said, your email has triggered a process here that made us re-examine that, and we're going to just go ahead and make the Source SDK freely available. Thanks for making us better!" When asked for confirmation by RPS, Walker added:
We are in the process of getting it all done. It’s a bit messy because we have multiple versions of the SDK, and there’s some dependencies we need to shake out. But yes, the gist of it is that we’re just going to go ahead and make the Source SDK freely available.
Valve is actually slightly late to the game on this one—Epic Games released its Unreal Development Kit for free back in November 2009. Last we heard, developers don't have to pay Epic a dime if they don't charge for their creation, and Epic has licensing terms tailored for indie developers who want to get paid. In any case, considering the illustrious history of mods for Valve games, the free release of the Source SDK is unarguably a good thing for the PC gaming community.