OWL: A DL-Based Ontology Language for the Semantic Web

It has long been realized that the web could benefit from having its content understandable and available in a machine processable form, and it is widely agreed that ontologies will play a key role in providing much enabling infrastructure to achieve this goal. In this chapter we review briefly some early efforts that combine Description Logics and the Semantic Web, in particular Oil and Daml+Oil. Oil and Daml+Oil are ontology languages specifically designed for use on the web; they exploit existing web standards (XML, RDF and RDFS), adding the formal rigor of a Description Logic and the ontological primitives of object-oriented and frame-based systems. We them go to describe OWL, the 3WC-recommended Web Ontology Language, in some detail. OWL extends the work in Oil and Daml+Oil, bringing Description Logic notions completely into the Semantic Web framework.