Zork is an interactive fiction computer game. It was originally developed by four members of the MIT Dynamic Modelling Group—Tim Anderson, Marc Blank, Bruce Daniels, and Dave Lebling–between 1977 and 1979 for the DEC PDP-10 mainframe computer. The four founded the company Infocom in 1979 and released Zork as a commercial game for personal computers, split due to memory limits of personal computers compared to the mainframe system. The three titles released commercially were Zork: The Great Underground Empire – Part I in 1980, Zork II: The Wizard of Frobozz in 1981, and Zork III: The Dungeon Master in 1982. The game has since been ported to numerous systems.