Three initial working draft documents on 'OWL' have been published by the W3C's Web-Ontology Working Group (WebOnt). OWL is a semantic markup language for publishing and sharing ontologies on the World Wide Web. OWL is derived from the DAML+OIL Web Ontology Language and builds upon the Resource Description Framework. The designers expect that OWL will support the use of automated tools which "can use common sets of terms called ontologies to power services such as more accurate Web search, intelligent software agents, and knowledge management." The OWL Web Ontology Language is being designed "in order to provide a language that can be used for applications that need to understand the content of information instead of just understanding the human-readable presentation of content. OWL facilitates greater machine readability of web content than XML, RDF, and RDF-S support by providing an additional vocabulary for term descriptions." The Feature Synopsis for OWL Lite and OWL introduces the OWL language. The OWL Web Ontology Language 1.0 Reference provides a systematic, compact and informal description of all the modelling primitives of OWL. An OWL knowledge base is a collection of RDF triples as defined in the RDF/XML Syntax Specification; OWL prescribes a specific meaning for triples that use the OWL vocabulary. The Language Reference document specifies which collections of RDF triples constitute the OWL vocabulary and what the prescribed meaning of such triples is. The OWL Web Ontology Language 1.0 Abstract Syntax document describes a high-level, abstract syntax for both OWL and OWL Lite, a subset of OWL; it also provides a mapping from the abstract syntax to the OWL exchange syntax.

From the Feature Synopsis for OWL Lite and OWL:

The OWL Web Ontology Language is being designed by the W3C Web Ontology Working Group in order to provide a language that can be used for applications that need to understand the content of information instead of just understanding the human-readable presentation of content. The OWL language can be used to allow the explicit representation of term vocabularies and the relationships between entities in these vocabularies. In this way, the language goes beyond XML, RDF and RDF-S in allowing greater machine readable content on the web. The OWL language is a revision of the DAML+OIL web ontology language incorporating [lessons learned] from the design and application use of DAML+OIL.

This document begins by describing a subset of the entire language called OWL Lite. The goal of OWL Lite is to provide a language that is viewed by tool builders to be easy enough and useful enough to support. One expectation is that tools will facilitate the widespread adoption of OWL and thus OWL language designers should attempt to create a language that tool developers will flock to. While it is widely appreciated that all of the features in languages such DAML+OIL are important to some users, it is also understood that languages as expressive as DAML+OIL may be daunting to some groups who are trying to support a tool suite for the entire language. In order to provide a target that is approachable to a wider audience, a smaller language has been defined, now referred to as OWL Lite. OWL Lite attempts to capture many of the commonly used features of OWL and DAML+OIL. It also attempts to describe a useful language that provides more than RDFS with the goal of adding functionality that is important in order to support web applications.

Bibliographic information:

• Feature Synopsis for OWL Lite and OWL. W3C Working Draft 29-July-2002. Edited by Deborah L. McGuinness (Knowledge Systems Laboratory, Stanford University) and Frank van Harmelen (Free University, Amsterdam). Version URL: http://www.w3.org/TR/2002/WD-owl-features-20020729/. Latest version URL: http://www.w3.org/TR/owl-features/.

• OWL Web Ontology Language 1.0 Reference. W3C Working Draft 29-July-2002. Edited by Mike Dean, Dan Connolly, Frank van Harmelen, James Hendler, Ian Horrocks, Deborah L. McGuinness, Peter F. Patel-Schneider, and Lynn Andrea Stein. Version URL: http://www.w3.org/TR/2002/WD-owl-ref-20020729/. Latest version URL: http://www.w3.org/TR/owl-ref/.

• OWL Web Ontology Language 1.0 Abstract Syntax. W3C Working Draft 29-July-2002. Edited by Peter F. Patel-Schneider, Ian Horrocks, and Frank van Harmelen. Version URL: http://www.w3.org/TR/2002/WD-owl-absyn-20020729/. Latest version URL: http://www.w3.org/TR/owl-absyn/.