Imaginary Realities was an electronic magazine for text games that existed in the late 1990's. It ran for four years, then in December 2001, the magazine abruptly stopped, and soon afterwards its content disappeared. It wasn't the only such magazine for text-based worlds, but it was the most successful.
During its run Imaginary Realities published over two hundred articles written by coders, administrators, builders, and players. The topics ranged from game design to player interaction to content development, and there's an article by one player who, moved by the death of another player, considered the impact of gaming on real life. The magazine published articles by some well-known names in the gaming field (e.g. Richard Bartle), and republished several articles that still influence games to this day. Its impact on text gaming was tremendous at the time.
When Imaginary Realities closed its doors, the text gaming community felt its loss. However, while the original site is forever gone, several sites have preserved and republished articles from the magazine. They include:
Imaginary Realities at the Wayback Machine - The Internet Archive Wayback Machine has done a very good job of preserving the content of Imaginary Realities, including several of the images, copyright information, author biographies, and more. Unfortunately, you cannot use the drop-down box at the top of every page of the magazine to skip between articles, and not all the articles exist (or if they do, they are hard to come by). Still, if you want to see how the magazine looked, and access some of the articles, the Wayback Machine is a good place to go.
Imaginary Realities at Tharsis Gate - This is the primary site for the online magazine's archives. The archiver did not retain images or author information. The articles, however, are generally intact.
The Complete Imaginary Realities Archive - Here at Grim Wheel, I've mirrored the zipped archive provided by Richard Tew above. It's not very big, and should that site go down, the articles will still be here.
The New Imaginary Realities - A second journal of the same name and focus began publishing in mid-December, 2013. While it seemed promising, IR's last issue came out in July, 2015, and the site itself disappeared a few years later. (Note that the link above actually goes to an archived version of the site.) Nonetheless the archive is still worth a visit.
Grim Wheel is a site dedicated to old school text gaming.
I haven't yet finished or opened most of the links below. An asterisk marks each of these.
Buildcraft* - Articles which discuss the craft of building on Multi-User Dungeons (MUDs).
MUD Forums - Links to offsite forums that concern themselves with all things related to Multi-User Dungeons.
MUD-Dev - Where you can find archives of the former mailing list known as "MUD-Dev", as well as a link to the newest mailing list.
Imaginary Realities - Archives of articles from the now-defunct online magazine Imaginary Realities.
MUD Listings* - Websites which list the many text games still in existence.
MUD Clients* - Clients which you can use to connect to an active MUD.
Codebases - The various public codebases in existence today.
Area Archives - Areas for public codebases such as Circle, ROM and Smaug.
Miscellaneous* - Links that do not fall easily into any category.