The Halo series is a popular series of first person shooter video games developed by Bungie Studios and published by Microsoft. The series follows a full-scale holy war  between future humanity and a collective of alien races known as The Covenant, which believe that seven ancient rings built by a long-dead race are religious icons, and activating them will propel The Covenant on the "Great Journey." The player follows the Master Chief, a genetically enhanced human equipped with the technologically advanced MIJOLNIR battle armor, as he, assisted by the Pillar of Automn's AI Cortana, helps the humans in their losing battle against The Covenant, and discovers the Halos' true purpose.

        Halo was the most popular application for the Xbox console up until the release of its more ambitious sequel, Halo2 . Halo quickly became known as the "killer app" for the newly introduced Microsoft Xbox console, gaining a huge success and later being ported to the PC and finally released for the originally intended platform, Apple macintosh. A second game was released in 2004, and the third game, currently thought to be in production, is rumored to be unveiled at E3, 2006 on May 9th. Halo games have become well known for their rich background development and engaging physics, characterstics they share with previous Bungie works, such as the Marathon series on the Mac. Further enriching the universe of Halo are several novels which provide insights into the background-story, and a movie currently in pre-production.