Infocom games, text adventures, and interactive fiction.
A Zcode interpreter written in Python. Plays Inform games (up to v7). Give it an Infocom game and it'll run it. I suspect that it can be included in or called from other code.
Just what it says on the tin. Implements Z-code with cheat commands so you can play Infocom games on whatever system you have Perl installed on. Supports multiple front-end interfaces.
A blog about classic games and science fiction, with a fair amount of interactive fiction stuff thrown in.
An online encyclopedia of all things infocom and Zork.