Other fascinating Interfactive Fiction sites.
Interactive Fiction Sites
 Interactive fiction games: More than retro fun  A nice introductory article to the delights of IF and Zork in particular.
 Brass Lantern  A great online magazine for players and writers of interactive fiction.
 Grand Text Auto  Collaborative weblog on all things IF.

Other Online Games or Interpreters
 Versificator - Online Text Adventures  Two, well written and implemented Javascript games available online.
 Parchment  A beautiful Javascript Z-Machine interpreter. Works well on modern desktop browsers.
 ZPlet  A Java applet based Z-Machine interpreter, works in a browser providing that you have a Java Runtime Environment installed.

Creating New Games
 Inform 7  A cross-platform IDE for creating Z-Machine games that you program in plain English (almost). A monumental piece of work, using this you'll have written your first game within hours.
 TADS 3  A more traditional language that creates TADS games which require a TADS interpreter to run.