opencyc
- The opencyc platform is your Gateway to the full power of Cyc, the world's largest and most complete general knowledge base and commonsense reasoning engine. OpenCyc contains hundreds of thousands of Cyc terms organized in a carefully designed ontology. Cycorp offers this ontology at no cost and encourages you to make use of, and extend, this ontology rather than starting your own from scratch. OpenCyc can be used as the basis of a wide variety of intelligent applications such as: