Marathon 2: Durandal was the first sequel in the Marathon series of science fiction first-person shooter computer games from Bungie Software. It was released on November 24, 1995. The game is mostly set on the fictional planet of Lh'owon, homeworld of the S'pht, and once again the player takes the role of a Security Officer from the Marathon.
Seventeen years have passed since the events of the first game. Durandal, one of the three AIs from the Marathon, sends the player and an army of ex-colonists to search the ruins of Lh'owon, the S'pht home-world. He does not mention what exactly he is looking for, although he does let it slip that the Pfhor are planning to attack Earth, and that being on Lh'owon may stall their advance. Marathon 2 brings many elements to the game that can be considered staples of the series such as: a Lh'owon-native species known as F'lickta, the mention of an ancient and mysterious race of advanced aliens called the Jjaro, and a clan of S'pht that avoided enslavement by the Pfhor - the S'pht'Kr. At the climax of the game, the Security Officer activates Thoth, an ancient Jjaro AI. Thoth then contacts the S'Pht'Kr, who in turn destroy the Pfhor armada.
Marathon 2 is the only game in the series to have been officially released for Windows 95 in addition to the Apple Macintosh. In 1996, it was combined with its predecessor Marathon into a port for Bandai's short-lived Pippin @WORLD console, titled Super Marathon, which is a rare collector's item today. It was re-released as part of the Marathon Trilogy box set for Macintosh on May 1, 1997. As of 2009, it is also the only one from the series to be officially released for the Xbox 360.
Bungie released source code and game content from the entire Marathon Trilogy in 2005. An open source project, Aleph One, was launched to allow the three games to be freely played on Mac OS X, Windows, Linux, and other platforms. Other features were added, including online play and support for higher-resolution graphics. The engine was also updated to support Bungie's previous work, such as Pathways into Darkness and the Marathon Zero beta.