Halo: Combat Evolved is a 2001 military science fiction first-person shooter video game developed by Bungie and published by Microsoft Game Studios. The first game of the Halo franchise, it was released as a launch titlefor the Xbox gaming system on November 15, 2001. More than five million copies were sold worldwide by November 2005. Microsoft released versions of the game for Microsoft Windows and Mac OS X in 2003, and the surrounding storyline was adapted and elaborated into a series of novels, comic books, and live-action web series. The game was later released as a downloadable Xbox Original for the Xbox 360. A high-definition remake, Halo: Combat Evolved Anniversary, was released for Xbox 360 on the 10th anniversary of the original game's launch, and was rereleased as part of Halo: The Master Chief Collection on November 11, 2014, for the Xbox One.