Return to Castle Wolfenstein (PC) is a first person shooter computer game published by Activision and released on November 20, 2001. The single player game was developed by Gray Matter Interactive and Nerve Software developed its multiplayer mode. Id Software, the creators of the original game entitled Wolfenstein 3D, oversaw the development of the game and were credited as executive producers. The multiplayer side, developed by Nerve Software, eventually became the best reason to own the game, and it grandfathered in many features that online multiplayer FPS's have today.