Zork, "The classic underground maze/puzzle." Zork is a text-based adventure game developed between 1977 and 1979 by Tim Anderson, Marc Blank, Bruce Daniels, and Dave Lebling of the MIT Dynamic Modelling Group. The version available on twenex.org is the pre-commercial version developed with the MDL language on a DEC PDP-10 mainframe computer.
To run Zork, enter the command ZORK.