The Lisp machine market collapses

In 1987 the market for Lisp machines, the workstations built to run the language of artificial intelligence, stopped. Sun Microsystems and Apple were selling general-purpose machines that ran Lisp nearly as well for a fifth of the price, and the expert systems that had justified special hardware were being written in C and shipped on ordinary computers. Symbolics, which had been the most profitable company in the field, lost most of its revenue within two years; Lisp Machines Inc. was gone; Texas Instruments closed its line. An industry of about half a billion dollars a year had disappeared.

The software companies went next. Expert systems had proved expensive to maintain, and the corporate AI departments set up in the boom were cut in the recession of the early 1990s. Venture capital left. DARPA's Strategic Computing money was winding down at the same time, and by 1990 researchers were using the term "AI winter", coined as a warning in 1984, to describe where they were.

The second winter was quieter than the first because the field had learned to avoid the word. Machine learning, pattern recognition, informatics: the work continued under other names, and some of it, LeNet and TD-Gammon among them, is on this timeline.