Infocom games were written using a roughly LISP-like programming language called ZIL ( Zork Implementation Language or Zork Interactive Language — it was referred to as both ) that compiled into a byte code able to run on a standardized virtual machine called the Z-machine.

Other popular and inventive titles included a number of sequels and spinoff games in the Zork series, The Hitchhiker's Guide to the Galaxy by Douglas Adams, and A Mind Forever Voyaging.

Five games ( Zork I, Planetfall, The Hitchhiker's Guide to the Galaxy, Wishbringer and Leather Goddesses of Phobos ) were re-released in Solid Gold format.

* The Gallery of Zork an updated version of the Infocom Gallery with higher-resolution photos, more material, such as more photos of earlier packaging, and online playable versions of the Infocom games.

Zork was one of the earliest interactive fiction computer games, with roots drawn from the original genre game, Colossal Cave Adventure.

That company adapted the PDP-10 Zork into Zork I-III, a trilogy of games for most popular small computers of the era, including the Apple II, the Commodore 64, the Commodore Plus / 4, the Atari 8-bit family, the TRS-80, CP / M systems and the IBM PC.

Personal Software published what would become the first part of the trilogy under the name Zork when it was first released in 1980, but Infocom later handled the distribution of that game and their subsequent games.

Part of the reason for splitting Zork into three different games was that, unlike the PDP systems the original ran on, micros did not have enough memory and disk storage to handle the entirety of the original game.

FrobozzCo products are littered throughout all Zork games, often with humorous effect.

) Although Wishbringer was never officially linked to the Zork series, the game is generally agreed to be " Zorkian " due to its use of magic and several terms and names from established Zork games.

Among the games bundled in The Lost Treasures of Infocom, published in 1991 by Activision under the Infocom brand, were the original Zork trilogy, the Enchanter trilogy, Beyond Zork and Zork Zero.

Activision's 1996 compilation, Classic Text Adventure Masterpieces of Infocom, includes all the text-based Zork games ; the Zork and Enchanter trilogies, Wishbringer, Beyond Zork and Zork Zero.

* Article at The Dot Eaters, featuring an extensive history of the Zork games and Infocom

* Mumboz Agrippa, a character from the Zork series of computer games

* Zork games such as Beyond Zork and Zork Zero came with " feelies " which contained information vital to the completion of the game.

In gaming culture, such a character was called Ageless, Faceless, Gender-Neutral, Culturally Ambiguous Adventure Person, abbreviated as AFGNCAAP ( pronounced " afgan-cap "); a term that originated in Zork: Grand Inquisitor where it is used satirically to refer to the player.

Langer of My So-Called Life as fellow Zork explorer Rebecca Snoot whom the player encounters on several occasions.

( At various points during play, the player had to provide information from the Encyclopedia, although the information was widely-known trivia from the Zork canon.

One of the repeated references in Zork's backstory was to the ancient king Entharion the Wise and the legendary blade Grueslayer, which he used to directly fight grues in combat ; this feat would not be repeated until the interactive fiction / RPG hybrid Beyond Zork, which allows a player who has advanced sufficiently in level and acquired certain items to boldly walk into the dark and kill grues that attack.

) Finally, the modern-day game Zork: The Undiscovered Underground created as a promotion for Zork Grand Inquisitor featured an extended reference to a line in Zork III about " a whole convention of grues " in a certain location, by having the player infiltrate a literal grue convention, complete with lectures, entertainment and souvenirs.

Presumably these are not the only instances in the Zork games when grues have been seen — one event in Sorcerer has the player finding a Frobozz Magic Company " anti-grue kit " ( admittedly a secret, experimental prototype ) that contains a grue costume which the player can don and thus travel among grues unharmed.

( The player in Zork: The Undiscovered Underground replicates this feat, albeit imperfectly.

This is part of the running gag of a series of mostly failed attempts to find some sort of alternate means of protection against grues in the event one's light source fails, most famously in Zork II where a can of Frobozz Magic Grue Repellent was included as a red herring — mostly useless, since it would only last for one game turn after one's light source expired, during which the player could not see his location anyway.

) In Zork III the Magic Grue Repellent functions more like the player might expect, and lasts for several turns.

However, in the Zork Trilogy, the player carries around an Elven sword that glows whenever he or she is near danger, the glow being described as a faint blue glow ( when one room away from a dangerous creature ) or a bright blue glow ( when in the same room ).

A possible parody of the concept appeared in one puzzle in Return To Zork, in which the player was in danger of being attacked by a grue after turning the light off in their own bedroom in a hotel ; the only solution is to place a piece of lightly glowing, magical rock called Illumynite on the nightstand, providing just enough light to ward off grues while still making it possible to sleep.

It is a ' point-and-click ' game on 2 CD-ROMs ( or one DVD that also includes Zork Nemesis ) that allows the player to look around in a full circle of 360 degrees at each pre-rendered location ( called ' Z-vision ').

When the player dies, the game cuts to a computer terminal on which the player's fatal action and its consequences appear in prose form, in the fashion of the original Zork trilogy.

Dalboz calls the player " AFGNCAAP ", a satirical, politically-correct initialism for " Ageless, Faceless, Gender-Neutral, Culturally-Ambiguous Adventure Person "— a joking reference to many adventure games, such as Infocom's original Zork games, in which the player's character has no identity, name, or background.

** In the early video game Zork ( 1977 – 79 ), the player must gather a bell, a book, and a candle in order to gain access to the lowest regions of Hell.

Games such as the popular Zork series of the late 1970s and early 1980s allowed the player to use a keyboard to enter commands such as " get rope " or " go west " while the computer describes what is happening.

Dungeon, the mainframe precursor to the commercial Zork trilogy, is generally assumed to be in the public domain and is available from The Interactive Fiction Archive as original FORTRAN source code, a Z-machine story file and as various native source ports.

Zork is set in " the ruins of an ancient empire lying far underground ".

( In each trilogy, there is a sense of assumed continuity ; that is, the player's character in Zork III is assumed to have experienced the events of Zork I and Zork II.

Similarly, events from Enchanter are referenced in Sorcerer and Spellbreaker ; but the Enchanter character is not assumed to be the same one from the Zork trilogy.

The latest installation of the Zork series is Legends of Zork, a persistent browser-based MMORPG, which was released on April 1, 2009, and shut down on May 31, 2011.

A full version of Zork I is playable on a computer terminal in the interrogation room in the 2010 game Call of Duty: Black Ops where it unlocks the achievement or bronze trophy ( Xbox 360 or PS3, respectively ) called " Eaten by a Grue.

Since January 18, 2011 Zork Anthology ( featuring Zork I, Zork II, Zork III, Beyond Zork, Zork Zero and Planetfall ) is internationally available at GOG. com, in a form of digital download.

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 troll "), but recognized some prepositions and conjunctions (" hit the troll with the Elvish sword ").

Infocom had used these concepts before only in a rather limited way in Zork I and III.

The Apple II's limited RAM required them to cut half of the original version of Zork.