The Suggested Upper Merged Ontology (SUMO) and its domain ontologies form the largest formal public ontology in existence today. They are being used for research and applications in search, linguistics and reasoning. SUMO is the only formal ontology that
I. Niles, and A. Pease. Proceedings of the International Conference on Formal Ontology in Information Systems - Volume 2001, page 2--9. New York, NY, USA, ACM, (2001)
I. Niles, and A. Pease. Proceedings of the 2nd International Conference on Formal Ontology in Information Systems (FOIS-2001), Ogunquit, Maine, (October 2001)