"Zork Zero: The Revenge of Megaboz is an interactive fiction computer game, written by Steve Meretzky and published by Infocom in 1988. Although it is the ninth and last Zork game released by Infocom before the company's closing, Zork Zero takes place before the previous eight games (Zork I, Zork II, Zork III, Enchanter, Sorcerer, Wishbringer, Spellbreaker and Beyond Zork). Unlike its predecessors, Zork Zero is a vast game, featuring a graphical interface with scene-based colours and borders, an interactive map, menus, an in-game hints system, an interactive Encyclopedia Frobozzica, and playable mini-games including Peggleboz and Double Fanucci. It is Infocom's thirty-second game."
Source: Wikipedia, "Zork_Zero," available under the CC-BY-SA License.