The Marathon Trilogy is a science fiction first-person shooter video game series from Bungie, originally released for Mac OS. The name Marathon is derived from the giant interstellar colony ship that provides the setting for the first game; the ship is constructed out of what used to be the Martian satellite Deimos. The three games in the series—Marathon (1994), Marathon 2: Durandal (1995), and Marathon Infinity (1996)—are widely regarded as spiritual predecessors of Bungie's Halo series.