Valve is handing Team Fortress 2 modders the keys to the kingdom, as long as they don't try to make any money from it. The company has added the client and server game code to the Source software development kit (SDK),

Valve: > Unlike the Steam Workshop or local content mods, this SDK gives mod makers the ability to change, extend or rewrite TF2, making anything from small tweaks to complete conversions possible. > The SDK is licensed to users on a non-commercial basis,

Do it yourself,” is how Team Fortress 2 players read Valve's recent decision to put the free-to-play FPS's official developer tools into the hands of the community.

Valve has released the Team Fortress 2 SDK, which means we can expect a load of new content from the modding community.

Team Fortress 2 has gotten a major update, as Valve opens up the modding scene even further to allow total overhauls to the game.

Team Fortress 2 maker Valve has handed over the game's full client and server code to fans, encouraging them to "change, extend or rewrite" TF2 in any non-commercial way possible. The code is now available via a "massive" update to the Source SDK [Software Development Kit],

An official blog post from Team Fortress 2 has announced the full release of the game's source code. Given the game's industry-defying longevity and especially-creative fanbase, it's likely we'll see an explosion of innovation from players in the months to come.