Mitchell Porter (
Fri, 30 Aug 1996 03:20:23 +1000

Cyc is an AI project, started in 1984 by Doug Lenat, whose objective
was to create a common-sense knowledge base - to avoid the brittleness
of specialist expert systems which "know" all about a limited technical
domain, but can't detect the contradiction in the statement that
"I'm 18 years old, and have held my current job for 20 years".
By 1995 there was a Cycorp, Inc., whose web is at,
and the knowledge base contained hundreds of thousands of propositions,
written in the CycL language.

The core of Cyc's "ontology" (implicit theory of reality, I suppose)
has been released on the web this month; you should be able to reach it at There are also plans to release
a Cyc inference engine and an HTML browser for the knowledge base (for
Unix, anyway), and the specifications of CycL. I gather that the plan is
to allow people to create specialized knowledge bases in their webs,
which will then become accessible for people using the inference engine.
Cycorp is apparently planning to keep most of its accumulated knowledge
base proprietary; it will be interesting to see how quickly a free
public-domain one develops on the web.