Web Ontology Language (OWL)

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6 September 2007: W3C Launches the OWL Working Group.

A. OWL is a Web Ontology language. Where earlier languages have been used to develop tools and ontologies for specific user communities (particularly in the sciences and in company-specific e-commerce applications), they were not defined to be compatible with the architecture of the World Wide Web in general, and the Semantic Web in particular.

OWL uses both URIs for naming and the description framework for the Web provided by RDF to add the following capabilities to ontologies:

OWL builds on RDF and RDF Schema and adds more vocabulary for describing properties and classes: among others, relations between classes (e.g. disjointness), cardinality (e.g. "exactly one"), equality, richer typing of properties, characteristics of properties (e.g. symmetry), and enumerated classes.

To participate in the development of the next versions of OWL, consider joining the OWL Working Group.

OWL Specification Development

The OWL suite of specifications consist of:

Tutorials

A set of tutorials on OWL and related Semantic Web technologies is maintained by the Semantic Web Best Practices and Deployment Working Group.

Articles and Presentations

We do not currently keep a separate list of OWL presentations and articles. See the Semantic Web presentations, W3C in The Press and Resource Description Framework Press.

Tools, Projects and Applications

The following is a small sample of the growing set of tools, projects and applications utilizing OWL.

Demos / Portals

The listing of developer’s tools on this page has been removed in July 2006, in favor of the more comprehensive page on the W3C Wiki. By moving this list to the Wiki, the Semantic Web community at large can contribute in keeping that information up-to-date.

Ontologies