The original Colossal Cave Adventure from 1976 was the origin of all text
adventures, dungeon-crawl (computer) games, and computer-hosted role-playing
games.

This is the last version released by Crowther & Woods, its original authors,
in 1995.  It has been known as "adventure 2.5" and "430-point adventure".

WWW: http://www.catb.org/~esr/open-adventure/