id Software, because they are awesome, has released the source code for Wolfenstein: Enemy Territory and Return to Castle Wolfenstein
id Software has released the source code of Splash Damage's Wolfenstein: Enemy Territory and Grey Matter's Return to Castle Wolfenstein as part of its QuakeCon festivities, letting everyone tinker under the hood of the Quake 3 engine-based shooters.
I really wish more companies would do this, when games are old and grey, if there's enough of a community around them release the source and let the hackers out there play and see what happens. id Software has been doing this since they released the source for Wolf3D, Doom, Quake, and a lot of other games, now adding the Wolf:ET to the list. Good stuff!