Agora: A repository of information regarding the design and development of online multi-user environments
Harley Hahn's Guide to Muds: An introduction to the basics of MUDs and mudding.
Mac OS MUDding Resource: Clients, Servers and general resources for mudders on Mac OS.
Mud Magic: Mud, mush, muck, text game listings, hosting, servers, snippets, articles and community.
MudWorld: Text game administrator resource site. Discussions, searches, and jobs.