GemStone IV is a multiplayer text-based online role-playing video game (often known as a MUD) produced by Simutronics. Players control characters in a High Fantasy game world named "Elanthia". The first playable version of the game was known as GemStone ][ and was launched in April 1988 on GEnie. It was one of the first MMORPGs and is one of the longest running online games still active.