Halo 3 is a 2007 first-person shooter video game developed by Bungie for the Xbox 360 console. The third installment in the Halo franchise following Halo: Combat Evolved (2001) and Halo 2 (2004), the game's story centers on the interstellar war between 26th-century humanity, a collection of alien races known as the Covenant, and the alien parasite known as the Flood. The player assumes the role of the Master Chief, a cybernetically enhanced supersoldier, as he battles the Covenant and the Flood. In cooperative play, other human players assume the role of allied alien soldiers. The game features vehicles, weapons, and gameplay elements familiar and new to the series, as well as the addition of saved gameplay films, file sharing, and the Forge map editor—a utility which allows the player to perform modifications to multiplayer levels.

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.