Valve have announced they will release their Source 2 engine for free to content developers.
Team Fortress 2 - Mann vs. Machine
A robot faction is introduced into the Team Fortress 2 equation, via this amazing new trailer by Valve.
Team Fortress 2 - ZombiU Crossover (Source Filmmaker)
This Team Fortress fan animation created with Source Filmmaker is a cool tribute to the ZombiU CG trailer.