XWebSOGO: an ontology language to describe and query web sources Edna Ruckhaus and Maria-Esther Vidal   View Paper (PDF)   Return to Tools for integrating and querying web information Abstract Ontologies play an important role in the Semantic Web. Currently, several Web ontology languages have been proposed and there has been a substantial effort towards the formalization of different knowledge domains. However, it is difficult to identify the ontologies for a specific domain and their annotated Web sources.XWebSOGO is a Web ontology language modeled after RDF and RDF Schema, that allows users to specify a domain in terms of its relevant entities' properties, the services that can be implemented on these entities, their query capabilities and the links that can connect them. In addition, XWebSOGO allows users to describe Web sources in terms of certain domain ontologies. Finally, XWebSOGO can be used to discover ontologies or Web sources that meet certain properties. XWebSOGOQL is a language used to query ontologies and annotated sources. An XWebSOGOQL query can be seen as a conjunctive query, where predicates are defined in terms of XWebSOGO basic concepts. In this paper, we define XWebSOGO and provide a formal definition of a query in XWebSOGOQL. ©2004 Association for Computing Machinery