Developer Bungie Studios and publisher Microsoft Game Studios released Halo 3, the third installment in the Halo franchise, in 2007 to conclude the trilogy's story arc. This Xbox 360 exclusive proved another huge success for the franchise. Over one million people played Halo 3 on Xbox Live within the first 24 hours of its release, and the game grossed a total of $300 million in its first week. Like its predecessors, Halo 3 is a first-person shooter game played in a 3D environment through the eyes of protagonist Master Chief Petty Officer John-117, a cybernetically altered supersoldier from the year 2552. The plot of the Halo series centers on an interstellar war being fought between humanity and an alien alliance known as the Covenant, complicated by a long history between an ancient intellectual race of Forerunners and a parasitic life form known as the Flood. Again joined by his artificial intelligence (AI) companions and crew, Master Chief enters the game after the events of Halo 2, crashing in eastern Africa and fighting the Covenant through the jungle to a United Nations Space Command outpost. The Covenant open a slipspace portal�Halo's version of faster-than-light travel�through which the characters travel to discover another artificial structure known as the Ark, and more potential destruction by Halo rings. After an intense and lengthy battle, Master Chief and his companions destroy the newest Halo ring and the Ark, but only Arbiter returns to Earth. Master Chief, drifting through space in the wreckage of his ship, goes into cryonic sleep with ominous words to Cortana: Wake me when you need me. Critics and gamers alike received Halo 3 as a satisfying ending to the trilogy, and as a game that, while not straying too far from the original or sequel, still gave players many new features to enjoy. Halo 3 contains new locales, vehicles, weapons, and a class of deployable items known as equipment that have special effects on gameplay or the environment. In terms of popular reception and critical praise, Halo 3 gained acclamation for its co-op mode. Halo 3 allows for four players in co-op mode simultaneously, and all can play over Xbox Live. In this mode, the game does not have to be played in a linear fashion��as long as the levels have already been unlocked during solo play, co-ops can play them in any order. In this mode players are also differentiated by new characters, instead of all acting as Master Chief. Furthermore, Halo 3 introduces a map-editing tool known as Forge, which became popular with both gamers and critics. Forge enables players to modify multiplayer maps in real time by spawning, removing or changing the location of weapons, vehicles and other items. Bungie also developed a way for players to save and share these creations through the web and Xbox Live. A player can publicly share items, go to Bungie's website to peruse their own and others' items, and then flag them for download to their personal console when they log in through Xbox Live. Players use the interface for customized objects as well as to share screenshots and gameplay videos. This new technology not only makes the game a more personal and customizable experience for a player, but also encourages gamer interaction and creativity.