Sven Co-op (abbreviated as SC) is a co-op variation of the 1998 first-person shooter Half-Life. The game, initially released as a mod on January 19, 1999, and created by Daniel 'Sven Viking' Fearon, enables players to play together on online servers to complete levels, many which are based on the Half-Life universe but include other genres. In addition to the cooperative gameplay, Sven Co-op includes improvements from the original Half-Life, including improved artificial intelligence for both enemy and allied non-player characters.