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.

Inspired by Colossal Cave, Marc Blank and Dave Lebling created what was to become the first Infocom game, Zork, in 1977 at MIT's Laboratory for Computer Science.

Zork I was released originally for the TRS-80 in 1980 and eventually sold more than a million copies across several platforms.

Even though Microsoft released a cheap version of Adventure with its initial version of MS-DOS 1. 0 for IBM PCs, Zork I was still a popular seller for the PC, thanks to the superior quality of its writing and packaging.

Although Infocom started out with Zork, and although the Zork world was the centerpiece of their product line throughout the Zork and Enchanter series, the company quickly branched out into a wide variety of story lines: fantasy, science-fiction, mystery, horror, historical adventure, children's stories, and others that defied categories.

For example, because Zork was available for years after its initial release in 1980, it continued to top charts in sales well into the mid-1980s.

Zork was ported under the filename " DUNGEN ", dungeon, to FORTRAN by a programmer working at DEC in 1978.

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.

In addition, Zork was written on the PDP-10, and Infocom used several PDP-10s for game development and testing.

The first version of Zork was written in 1977 – 1979 using the MDL programming language on a DEC PDP-10 computer.

" Zork " was originally MIT hacker slang for an unfinished program.

Zork I was published on 5¼ " and 8 " floppy disks.

The trilogy was written in ZIL, which stands for " Zork Implementation Language ", a language similar to LISP.

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.

In the process, more content was added to Zork to make each game stand on its own.

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 ").

Enchanter was originally developed as Zork IV ; Infocom decided to instead release it separately, however, and it became the basis of a new trilogy.

) 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.

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.

At one point the game mentions the " Implementers " who were responsible for creating the land of Zork.

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.

A fictional architect by the name C. Agrippa was charged to design and construct the great Temple of Agrippa which is one of the five major environments in the alchemy-themed adventure game Zork Nemesis.

) However, an actual illustration of a grue had been seen previously, although in an obscure source — one of Steve Meretzky's Zork gamebooks purposely included a section where the protagonists see a grue face-to-face before being eaten by it, presumably as a way to make the book attractive to Zork fans.

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.

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.

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.

: The large emerald is also one of the Twenty Treasures of Zork from the Infocom text adventure Zork I.

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 ').

Zork Grand Inquisitor was one of the first computer games to include true closed captioning so that the hearing impaired could play without missing any of the sound effects and spoken dialog in the game.

Tim Anderson is a computer programmer who helped create the adventure game Zork, one of the first works of interactive fiction and an early descendant of ADVENT ( also known as Colossal Cave Adventure ).

It was also intended, at one point, to be a sequel of sorts to the Zork trilogy.

The player's character in Zork: Nemesis is never identified, but the hint book refers to the character as " she ," and one male NPC looks at the main character and remarks, " Hey, you're beautiful!

Zork: Nemesis was one of the largest games of its time, occupying three CD-ROMs.

It was one of the last games in Infocom's Zork series ; or, rather, one of the last Zork games that many Infocom fans consider " official " ( titles such as Zork: Nemesis and Zork Grand Inquisitor were created after Activision had dissolved Infocom as a company and kept the " brand name ").

* Zork ( 1977 )-the earliest versions

** Zork Quest: Assault on Egreth Castle ( 1988, Infocom, interactive computer comic book )

** Zork Quest: The Crystal of Doom ( 1989, Infocom, interactive computer comic book )

2010 saw Zork I, Zork II, Zork III, and Mini-Zork formatted specifically for the Amazon Kindle – with more interactive text adventures promised for the platform.

* Play Zork online at THCNET's interactive 404 error page.

* Zork Implementation Language, the language which Infocom used to produce their works of interactive fiction

There is a phonetic similarity to the name Grue, a monster in the interactive fiction game Zork.

Text-based interactive fiction conventionally has descriptions written in the second person ( though exceptions exist ), telling the character what he is seeing and doing, such as Zork.

Dave Lebling introduced a similar monster, whose name was borrowed from Vance's grues, into the interactive fiction computer game Zork, published by Infocom.

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.

They have cropped up in other fantasy realms, though rarely, as they are seen as being strongly attached to the Zork universe, Infocom and the medium of interactive fiction in general.

An interactive fiction game known as Zork, sometimes called Dungeon, was first written in MDL.

Brian Moriarty ( born 1956 ) is an American video game developer who authored three of the original Infocom interactive fiction titles, Wishbringer ( 1985 ), Trinity ( 1986 ) and Beyond Zork: The Coconut of Quendor ( 1987 ).

It builds upon the Zork and Enchanter series of interactive fiction computer games originally released by Infocom.

Beyond Zork ( full title: Beyond Zork: The Coconut of Quendor ) is a interactive fiction computer game written by Brian Moriarty and released by Infocom in 1987.

The game is a text adventure similar to other early titles like Adventure ( 1976 ) or Zork ( 1980 ), though with many role-playing elements not available in other interactive fiction.

Parsers are used in early interactive fiction games like the Zork series, and more recently in games created by systems like Inform and TADS.

Zork Zero: The Revenge of Megaboz is an interactive fiction video game, written by Steve Meretzky over nearly 18 months and published by Infocom in 1988.

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 graphical mini-games.

Zork: The Undiscovered Underground ( or ZUU for short ) is an interactive fiction video game written by former Infocom Implementors Marc Blank and Michael Berlyn and implemented by G. Kevin Wilson using the Inform language.