- Valve has opened up Team Fortress 2’s full client and source code, encouraging players to ‘change, extend, or rewrite’ the game in any way they like.
- However, all mods must be released for free.
- Team Fortress 2 is nearing its 20th anniversary, with the class-based first-person shooter first released in 2007.-
Not really how patents work. It does not matter if the code is open or not, others are still not allowed to use patented code elsewhere or at least not commercially. (Not talking about the legitimacy of software patents)