http://www.asstr.org/~Broken_Arrow/IF/
Slutworld is an interactive fiction game much in the style of the old Infocom games, however, this one is clearly for adults only.
Still in development, but feel free to check it out :)
If you’ve never played parser-based interactive fiction before, you might like to play through this tutorial game first: http://playfic.com/games/cooper/tutorial
Also, reading this might help :) http://www.mrbillsadventureland.com/howto/intfiction/textplay.htm