Links To Classic Text Adventures:

Telehack. Telnet to telehack.com port 23 and type "help". These folks maintain a terrific archive of classic computer games, including a 1981 Zork ported to the Inform interactive fiction platform, and a very cool ADVENT.
Colossal Cave Adventure, with a very nice Web GUI, by Matt Mastracci.
Halt and Catch Fire, a great GUI-based ADVENT.

"The criticism/creation dichotomy automatically becomes, in a digital world, a dynamic oscillation: you simply cannot be a critic without being in turn a creator."
— Richard Lanham, The Elecronic Word (info)