"Zork" was originally MIT hacker jargon for an unfinished program. The implementors named the completed game Dungeon, but by that time the name Zork had already stuck. Zork has also been adapted to a widely panned book series. Zork and its relatives are works of interactive fiction. Zork distinguished itself in its genre as an especially rich game, in terms of both the quality of the storytelling and the sophistication of its text parser, which was not limited to simple verb-noun commands ("hit grue"), but some prepositions and conjunctions ("hit the grue with the Elvish sword").