Interactive Fiction Link Directory

The Interactive Fiction Archive is of course the ur-resource for all things IF.

Community websites

International

Other

Website of the ifMUD, the community’s oldest hangout besides the now defunct newsgroups.

Books and Publications

Authoring

Too many authoring systems to list, but Roger Firth’s Cloak of Darkness provides a good overview.

Last but not least, here’s another resource list by Emily Short, and one more by Hannah Powell-Smith.