Zork © 1979 Infocom, Inc.
Zork is set in the ruins of an ancient empire lying far underground. The player is a nameless adventurer who is venturing into this dangerous land in search of wealth and adventure. The goal is to return from exploring the 'Great Underground Empire' (GUE, for short) alive and with all treasures needed to complete each adventure, ultimately inheriting the title of Dungeon Master. The dungeons are stocked with many novel creatures, objects, and locations, among them the ferocious but light-fearing grues, zorkmids (the GUE's currency), and Flood Control Dam #3—all of which are referenced by subsequent Infocom text adventures.
A bunch of university kids at MIT (soon to be the guiding lights behind Infocom) played the pioneering cave-crawling treasure-hunting text game ADVENTURE and thought they can improve it. Around June of 1977 they pooled their collected creative juices and cranked out a sassy successor in MDL on a PDP-10. It didn't have a name, so they just used a hacker nonsense word in place of one temporarily ZORK.
Written by: Dave Lebling, Marc Blank, Tim Anderson, Bruce Daniels