Quake 4 is the fourth title in the series of Quake first-person shooter computer games. The game was developed by Raven Software and distributed by Activision. Raven Software has collaborated with id Software, the creators and historical developers of preceding Quake games. In this case, id Software supervised the development of the game as well as providing the Doom 3 engine, now referred to as 'id Tech 4', upon which it was built. Quake 4 went gold in early October 2005 and was released on October 18, 2005 for the PC, and later for the Xbox 360 and the Apple Macintosh. A special DVD Collectors Edition also exists, including promotional material and the game Quake II with its expansions, The Reckoning and Ground Zero. The Xbox 360 version of Quake 4 is based on the Special Collectors Edition, and therefore also includes Quake II.