OWL ascends within standards group

As part of its ongoing effort to give digital documents meaning that computers can understand, the Web's leading standards body advanced a key protocol as a candidate recommendation.

The World Wide Web Consortium's (W3C) Web Ontology Language (OWL), a revision of the DAML+OIL Web ontology language, forms just one part of what the consortium calls its "growing stack" of Semantic Web recommendations.

The W3C for years has braved skepticism directed at its Semantic Web initiative, which aims to get computers to "understand" data rather than to just transfer, store and display documents for computer users.

Other documents in the Semantic Web stack include the Extensible Markup Language (XML), a general-purpose W3C recommendation for creating specialized markup languages, and the Resource Description Framework (RDF), which integrates different methods of describing data.

OWL, by contrast, goes a step beyond existing recommendations to provide for more detailed descriptions of content.

"OWL can be used to explicitly represent the meaning of terms in vocabularies and the relationships between those terms," according to the W3C's OWL overview, the first of the set of six OWL drafts released Monday. "This representation of terms and their interrelationships is called an ontology. OWL has more facilities for expressing meaning and semantics than XML (and) RDF...and thus OWL goes beyond these languages in its ability to represent machine interpretable content on the Web."

This week's releases are more than three months behind schedule. In April, the W3C released OWL working drafts and promised a candidate recommendation by May 9.

OWL, which comes in three subsets of varying complexity, is open to comment until at least Sept. 20, after which it will be eligible for the W3C's "proposed recommendation" status, the next-to-last stop in the group's process.

Members of the W3C's Web Ontology Working Group include representatives of Philips Electronics, the Defense Information Systems Agency, Hewlett-Packard, Sun Microsystems, Fujitsu, Nokia, Stanford University, Motorola, IBM and Unisys.