It has come to my attention (thank you reader) that the Zork link I mentioned way back in August 2005 isn’t working reliably.
So if you want a nice quiet game try
Play Infocom Adventures Online
The games run in Java and are still as much fun ( slippery little concept that fun one) as they ever were.
Here is the list.
Zork I: The Great Underground Empire
Zork II: The Wizard of Frobozz
Zork III: The Dungeon Master
Zork: The Undiscovered Underground
The Hitchhiker’s Guide to the Galaxy
Leather Goddesses of Phobos
The Lurking Horror
Also be aware that SAVE and RESTORE may not available due to various security restrictions (applet, your browser, the phase of the moon), so do a test save before you get too far down the track.
Also watch out for grues in the Zork games.