The first (and very successful) game "Zork" was created in 1977, 2 years before the creators founded the company "Infocom", let alone released the game (which finally occurred in 1980).
Other popular (and innovative) titles included the rest of the "Zork" series, 1984's "The Hitch Hikers Guide To The Galaxy", and 1985's "A Mind Forever Voyaging".
In 1986, Infocom merged with Activision?, another great in the computer gaming industry.
Many Infocom titles remain available throughout the Internet community (legally in the case of the Zork trilogy, but illegally in most other cases). They are available as Z-machine story files, which require a Z-machine emulator (a Z-code interpreter) to play. These interpreters have been written for numerous platforms, ranging from older computers to palmtops to the IBM PC and Macintosh, and even Java.
An excellent site detailing a timeline of Infocom's founding, releases and eventual dissolution, can be found at http://www.csd.uwo.ca/Infocom/Articles/timeline.html.