|Publisher(s)||Microsoft Game Studios|
|Years active||November 15, 2001–present|
|System(s)||Xbox, Windows, Xbox 360|
|Mode(s)||Single player, Multiplayer|
Halo is a science fiction video game series created by Bungie Studios and published by Microsoft Game Studios. The series centers on the Master Chief, a cybernetically enhanced human super-soldier equipped with technologically-advanced battle armor, and his artificial intelligence (AI) companion, Cortana, as the humans of a futuristic universe battle the Covenant, a theocratic alliance of alien races.
The video games, particularly Halo: Combat Evolved, have been praised as being among the best first-person shooters on a game console, with Halo being the Microsoft Xbox's "killer app". This has led to the term "Halo killer" being used to describe console FPS games that aspire to be better than Halo.
Halo 2 was the highest grossing release in entertainment history, taking $125m in its first 24 hours on sale, and Halo 3 sold more than US $170 million worth of copies in the first 24 hours of release, breaking the previous installment's record. As of October 4, 2007, all three Halo games combined have sold more than 20 million copies.
The strong sales of the game series have led to a massive Halo franchise. Currently, this includes five bestselling novels, two series of graphic novels, and numerous other licensed products, from action figures to Mountain Dew. Several spin-off games have also been announced, including the upcoming real time strategy game Halo Wars and Halo Chronicles, which is being developed by Peter Jackson.