The first version of Zork was written 1977-1979 on a PDP-10 computer by Tim Anderson[?], Marc Blank[?], Bruce Daniels[?], and Dave Lebling[?] in a programming language called MDL[?]. All the programmers came from the Dynamic Modelling Group[?] at the MIT Artificial Intelligence Lab[?].
Originally "Zork" was a name that any unfinished program around MIT got. When the game was finished the implementors called it Dungeon, but people went on calling it Zork, so the name stuck.
The company Personal Software[?] produced a version of Zork I (about the first third of the original Zork) for the Apple II and TRS-80 personal computers in 1980. They managed to fit this much capability into the small personal computer systems of the time, and gain portability between them, by using a specialized system called the Z-machine. They had plans to release Zork II as well, but never got that far.
Zork and its relatives fit into a category known as interactive fiction.
The original Zork trilogy:
The Enchanter Trilogy also took place in the Zork universe and is considered to be part of the Zork series:
Later Infocom additions to the series:
Even later Activision additions to the series: