Legends of Zork is based on the original game, titled simple “Zork.” Below is a bit from Wikipedia describing the game.
Zork was one of the first interactive fiction computer games and an early descendant of Colossal Cave Adventure. The first version of Zork was written in 1977–1979 on a DEC PDP-10 computer by Tim Anderson, Marc Blank, Bruce Daniels, and Dave Lebling, and implemented in the MDL programming language. All four were members of the MIT Dynamic Modelling Group.
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”).
The game has been modified and “upgraded” to a browser-based game with its own website. A classic game, I felt it was good to share it.