Return to Castle Wolfenstein is a first-person shooter game published by Activision, released on November 19, 2001 for Microsoft Windows and subsequently for PlayStation 2, Xbox, Linux and Macintosh. The game serves as both a remake and a reboot to the Wolfenstein series. This single player game was developed by Gray Matter Interactive and Nerve Software developed its multiplayer mode. Id Software, the creators of Wolfenstein 3D, oversaw the development and were credited as executive producers.[ The multiplayer side eventually became the most popular part of the game, and was influential in the genre. Splash Damage created some of the maps for the Game of the Year edition. A loose sequel, titled Wolfenstein, was released on August 18, 2009.