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.
The W3C Semantic Web Activity Statement explains W3C's plans for OWL deployment, including the Web Ontology Working Group, Best Practices and Deployment Working Group and the Semantic Web Interest Group.
The OWL suite of specifications consist of:
formerly Feature Synopsis for OWL Lite and OWL
The OWL Web Ontology Language is designed for use by applications that need to process the content of information instead of just presenting information to humans. OWL facilitates greater machine interpretability of Web content than that supported by XML, RDF, and RDF Schema (RDF-S) by providing additional vocabulary along with a formal semantics. OWL has three increasingly-expressive sublanguages: OWL Lite, OWL DL, and OWL Full.
W3C Recommendation 10 Feb 2004. Smith, Welty, McGuinness, eds.
W3C Recommendation 10 Feb 2004, 12 November 2002. Dean, Schreiber, eds.
W3C Recommendation 10 Feb 2004. Patel-Schneider, Hayes, Horrocks, eds.
W3C Recommendation 10 Feb 2004. Jeremy J. Carroll, Jos De Roo, eds.
W3C Recommendation 10 Feb 2004. Jeff Heflin, ed.
Masahiro Hori, Jérôme Euzenat, Peter F. Patel-Schneider. W3C Note 11 June 2003
A set of tutorials on OWL and related Semantic Web technologies is maintained by the Semantic Web Best Practices and Deployment Working Group.
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.
The following is a small sample of the growing set of tools, projects and applications utilizing OWL.
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.
