The Jargon File (version 4.4.7, 29 Dec 2003):

Infocom
 n.

    A now-legendary games company, active from 1979 to 1989, that
    commercialized the MDL parser technology used for Zork to produce a line
    of text adventure games that remain favorites among hackers. Infocom's
    games were intelligent, funny, witty, erudite, irreverent, challenging,
    satirical, and most thoroughly hackish in spirit. The physical game
    packages from Infocom are now prized collector's items. After being
    acquired by Activision in 1989 they did a few more ?modern? (e.g.
    graphics-intensive) games which were less successful than reissues of their
    classics.

    The software, thankfully, is still extant; Infocom games were written in a
    kind of P-code (called, actually, z-code) and distributed with a P-code
    interpreter core, and not only open-source emulators for that interpreter
    but an actual compiler as well have been written to permit the P-code to be
    run on platforms the games never originally graced. In fact, new games
    written in this P-code are still being written. There is a home page at
    http://www.csd.uwo.ca/Infocom/, and it is even possible to play these games
    in your browser if it is Java-capable.