AKT Reference Ontologies
Various ontologies developed in the framework of the Advanced Knowledge Technologies project. Includes a portal ontology.
Business Process Management Ontology
BPMO is an integrated information model including business process design, project management, requirements management, and business performance management.
DAML Ontology Library
An index of more than 200 publicly available ontologies expressed in DAML.
Descriptive Ontology for Linguistic and Cognitive
DOLCE is the first module of the WonderWeb Foundational Ontologies Library (WFOL).
Mapping of EuroWordnet Top Ontology into Upper Cyc
The main EuroWordnet concepts mapped to corresponding Cyc constants through dynamic pages.
National Cancer Institute Thesaurus
An OWL translation of the NCI Thesaurus, available for download (32 Mb) or online viewing.
Ontology for Geographic Information and Metadata
An OWL publication of the ISO 19115 standard, from Drexel University.
Open Biological Ontologies
Provides access to controlled vocabularies for shared use across different domains, like MESH and Gene Ontology.
OpenCyc
OpenCyc is the open source version of the Cyc technology, the world's largest and most complete general knowledge base and commonsense reasoning engine.
OWL Ontology Library
A selection of OWL ontologies usable in Protégé.
Semantic Web for Earth and Environmental Terminolo
Several ontologies published by the Jet Propulsion Laboratory in OWL format. Includes Space, Units, Earth Realms, Phenomena, Physical Properties, Substances and Units.
Suggested Upper Merged Ontology
A free, formal ontology in first order logic with domain ontologies totalling 20,000 concepts and 60,000 axioms, with mappings to all of WordNet.
The Enterprise Ontology
Collection of terms and definitions relevant to business enterprises. Developed in the Enterprise Project by the Artificial Intelligence Applications Institute at the University of Edinburgh.
ThoughtTreasure
A web-accessible ontology system with terms in English and French. A downloadable version is also available.