Valve just released the source code for Team Fortress 2 — on purpose

Valve just released the entirety of the Team Fortress 2 client and server source code, and it wasn’t even an accident. In a ...
Engadget

Valve hands the Team Fortress 2 source code to modders

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 ...
TechSpot

Valve releases full Team Fortress 2 SDK, modders gain control over the game's code

Why it matters: Team Fortress 2 launched 17 years ago but still receives significant updates, and its player base is as healthy as ever. The latest patch fully unlocks the game's SDK, releasing ...