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.

Whereas most game developers sold their games mainly in software stores, Infocom also distributed their games via bookstores.

Unlike most computer software, Infocom titles were distributed under a no-returns policy, which allowed them to make money from a single game for a longer period of time.

Sometimes, though, Infocom threw in puzzles just for the humor of it — if the user never ran into these, they could still finish the game just fine.

In an attempt to reach out to females, Infocom also produced Plundered Hearts, which required the gamer to take the part of a heroine in a swashbuckling adventure on the high seas, and which required the heroine to use more feminine tactics to win the game, since hacking-and-slashing was not a very ladylike way to behave.

And to compete with the Leisure Suit Larry style games that were also appearing, Infocom also came out with Leather Goddesses of Phobos in 1986, which featured " tame ", " suggestive ", and " lewd " playing modes, and that was notable for including among its " feelies " a " scratch-and-sniff " card with six odors that corresponded to six cues during the game.

Infocom had sunk much of the money from games sales into Cornerstone ; this, in addition to a slump in computer game sales, left the company in a very precarious financial position.

These compilations featured nearly every game produced by Infocom before 1988.

* The Infocom Gallery with photos of all game boxes, feelies, instruction manuals and extra game contents.

* The Infocom Project High-quality scans of game boxes and contents.

* Most of the 1986 Infocom game Leather Goddesses of Phobos occurs ( despite the name ) on Mars.

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

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.

A licensed interactive fiction game based on the script was being developed for Infocom by Bob Bates, but was cancelled when Infocom was shut down by its then-parent company Activision.

Suspended: A Cryogenic Nightmare is an interactive fiction video game written by Michael Berlyn and published by Infocom in 1983.

Still, Suspended was a highly regarded game ; science fiction writer Douglas Adams, an early fan of Infocom games, was particularly taken with it.

* Enchanter ( video game ), a 1983 interactive fiction game by Infocom

A second example of Vogon poetry is found in the Hitchhiker's Guide interactive fiction game that was produced by Infocom.

The Infocom interactive fiction game Trinity begins in the Kensington Gardens.

It was developed by Activision and was the final Zork game to be published under the Infocom label.

It is possible to kill several of the game's civilian non-player characters, whereas in every other Infocom or Zork game, such actions are either impossible to accomplish or immediately punished by death.

This allows authors of modern games to ship one file containing everything needed to play the game, while also allowing the creation of resource files for classic Infocom games without running the risk of copyright infringement by distributing Infocom's Z-machine executable code.

The final paragraph about the Infocom game and the Hitchhiker's script book is omitted, however the phone number for NASA in the included translation of " How to Leave the Planet " has been updated for their new area code.

There are currently at least four Infocom sampler and demos available from the IF Archive as Z-machine story files which require a Z-machine interpreter to play.

Infocom itself used extensions of. dat ( Data ) and. zip ( ZIP = Z-machine Interpreter Program ), but the latter clashes with the present widespread use of. zip for PKZIP-compatible archive files starting in the 1990s, after Activision had shut down Infocom.

Only two version 1 files are known to have been released by Infocom, and only two of version 2.

The compiler ( called Zilch ) which Infocom used to produce its story files, has never been released, although documentation of the language used ( called ZIL, for Zork Implementation Language ) still exists and an open-source replacement ( called ZILF ) has been written.

During the 1990s, Graham Nelson drew up a Z-machine standard, based on detailed studies of the existing Infocom files.

* Blorb files for Infocom games

This marked one of the few major additions to the Z-machine with the exception of graphics ; traditionally, Infocom had eschewed such changes in favor of expanding the parser capacity and overall size of game files.

With the Z-machine, Infocom was able to release most of their games for most popular home computers of the day simultaneously — the Apple II family, Atari 800, IBM PC compatibles, Amstrad CPC / PCW ( one disc worked on both machines ), Commodore 64, Commodore Plus / 4, Commodore 128, Kaypro CP / M, Texas Instruments TI-99 / 4A, the Mac, Atari ST, the Commodore Amiga and the Radio Shack TRS-80.

The Z-machine is a virtual machine that was developed by Joel Berez and Marc Blank in 1979 and used by Infocom for its text adventure games.

Infocom produced six versions of the Z-machine.

* Infocom used the Z-machine to make its software applications more portable.

Such virtual machines exist for several platforms, and in this respect, TADS closely follows the example of the original Infocom Z-machine, as well as modern languages such as Java and C #.

It was also the first of the " Interactive Fiction Plus " line, meaning that AMFV had greater memory requirements, unlike earlier Infocom games that used a less advanced version of the company's Z-machine interpreter.

* A software compiler used by Infocom to create Z-machine games.

Like most Infocom games, thanks to the portable Z-machine, it was released for several platforms simultaneously.

Since all Z-machine games were produced by Infocom, there was also no chance that resources would be shipped in a format which a user's interpreter program could not handle.

* Stationfall at the Infocom Gallery has scans of the instructions and feelies that shipped with Stationfall