Halo: Combat Evolved is a 2001 first-person shooter video game developed by Bungie and published by Microsoft Game Studios for the Xbox. It was released as a launch game for Microsoft's Xbox video game console on November 15, 2001. The game was ported to Microsoft Windows and Mac OS X in 2003. It was later released as a downloadable Xbox Original for the Xbox 360. Halo is set in the twenty-sixth century, with the player assuming the role of the Master Chief, a cybernetically enhanced supersoldier. The Chief is accompanied by Cortana, an artificial intelligence. Players battle aliens as they attempt to uncover the secrets of the eponymous Halo, a ring-shaped artificial world.

Bungie, Inc. is an American video game company based in Bellevue, Washington, and a subsidiary of Sony Interactive Entertainment. The company was established in May 1991 by Alex Seropian, who later brought in programmer Jason Jones after publishing Jones's game Minotaur: The Labyrinths of Crete. Originally based in Chicago, Illinois, the company concentrated on Macintosh games during its early years and created two successful video game franchises called Marathon and Myth. An offshoot studio, Bungie West, produced Oni, published in 2001 and owned by Take-Two Interactive, which held a 19.9% ownership stake at the time.