The Unofficial Infocom Home Page -- the best place to find information on Infocom.

Adventureland "tries to list all adventure games (interactive fiction) produced over the years". It's a good list that covers the companies and authors that made the games, which computers they came out on, etc. **New location**

Baf's Guide to the Interactive Fiction Archive will help you navigate the Interactive Fiction Archive at IFarchive.org..

Doe, at Doe's Interactive Fiction Page, is the hostess for the IF ArtGallery, presents "An Iffy Theory", and tells the tale of The Storybook Kingdom of IF.

The Chronology of Quendor has a detailed timeline of the Great Underground Empire.
Note: Robin moved the Chronology to a slightly different section of his website a few months back. If your bookmark doesn't say http://quendor.robinlionheart.com, it's out of date.

The Encyclopedia Frobozzica compiles the various facts about the land of Quendor that is scattered throughout the Zork games. The Encyclopedia is also available in PDF and .z5 formats.
Note: this is the older version. I'm currently tracking down the 2001 Edition.

The Frobozz Electric WebSite #50809 concentrates on the Zork titles, and does an excellent job. It has a Brief History of Zork, screenshots and character profiles from the games, and more.

In The Zork Library, you'll find an illustrated Chronologue (timeline) of the Great Underground Empire, a Zork font, and bit more, including a Zork game they are working on called Zork: The Hidden Evil.

Graem Cree's website offers two useful sections: Infonotes and The Infocom Bugs List. Infonotes describes what changed in the different releases of each Infocom games. The Infocom Bugs List identifies the bugs that showed up over the years.

Similarly, The Infocom Version List tracks statistics on the different releases of the Infocom games that can be useful to people playing the games through various interpreter programs.

The Infocom Potpourri Website contains information on early Infocom products, like Fooblitzky and the Zork Users Group map for Zork III.

Interactive Fiction on the Web is a site that used to greet you with a message that it "will bring you everything you need to know about interactive text adventures. Whether you want to play one, write one, or just get hints. Low cunning not required."

PDD's Adventure Page offers a useful collection of links tracing the history of text adventures.

Preserving Classic Adventures Project (PreCAP) is another attempt to preserve games before they become lost irrevocably.

The Text Adventure Shrine "contains information relating to text adventures or interactive fiction (IF) as many prefer to call them."

Suzanne Britton's The World of Interactive Fiction has her "Best of IF List", the Worlds Apart IF tale she wrote, a history of the IF Authoring Competition, humor from the IF world, and quite a bit more.

The Ur-Grue maintains two websites: Ur-Grue's Lair and Free Working Infocom Sample Transcripts. The second website also contains three-dimensional maps of Planetfall.

Though The Zork Shrine hasn't been updated for a few years, the "Zork FAQ" contains a good history on Infocom and Zork, written in a question-and-answer style.