Cyc

Cyc (/ˈsaɪk/) is an artificial intelligence project that attempts to assemble a comprehensive ontology and knowledge base of everyday common sense knowledge, with the goal of enabling AI applications to perform human-like reasoning.

The project was started in 1984 by Douglas Lenat at MCC and is developed by the Cycorp company. Parts of the project are released as OpenCyc, which provides an API, RDF endpoint, and data dump under an open source license.

The project was started in 1984 as part of Microelectronics and Computer Technology Corporation. The objective was to codify, in machine-usable form, millions of pieces of knowledge that compose human common sense. CycL presented a proprietary knowledge representation schema that utilized first-order relationships. In 1986, Doug Lenat estimated the effort to complete Cyc would be 250,000 rules and 350 man-years of effort. The Cyc Project was spun off into Cycorp, Inc. in Austin, Texas in 1994.

The name "Cyc" (from "encyclopedia", pronounced [saɪk] like syke) is a registered trademark owned by Cycorp. The original knowledge base is proprietary, but a smaller version of the knowledge base, intended to establish a common vocabulary for automatic reasoning, was released as OpenCyc under an open source (Apache) license. More recently, Cyc has been made available to AI researchers under a research-purposes license as ResearchCyc.