W3C is pleased to receive the Semantic Web Services Framework (SWSF) Submission from National Institute of Standards and Technology (NIST), National Research Council of Canada, SRI International, Stanford University, Toshiba Corporation, and University of Southampton.
This Submission describe a language, SWSL, and an ontology, SWSO, for describing aspects of Web Services. SWSO is intended to model service behavior, complementing WSDL which can be used to describe invocation details. SWSL is divided into a SWSL-FOL, a first order logic language, and SWSL-Rules, a rule-based language for service discovery, contracting, and policy specification. SWSL-Rules is compatible with Logic Programming. SWSO is designed to cover a wide range of uses:
The Semantic Web Services Language (SWSL) specification includes an analysis of the relationship between SWSL-FOL and SWSL-Rules, aimed to maximize interoperability between the two languages. Both SWSL languages are serialized using RuleML's XML syntax (though the specification defines and uses an F-Logic shorthand) and, like RuleML, divides the language's expressivity into orthogonal components (called layers in SWSL).
SWSO abstractly models existing Web Service technologies, including WSDL, WSBPEL, and WS-CDL. The Submission explores SWSO's relationship to WSDL 1.1 and 2.0, BPEL4WS 1.1 and also the WSMO Submission received in 2005 by W3C, but not to WS-CDL 1.0. SWSO-FOL was presented at the W3C Workshop on Frameworks for Semantics in Web Services (see FLOWS: A First-Order Logic Ontology for Web Services).
This Submission addresses the same space as the OWL-S Submission, but where OWL-S is written in OWL (a 2004 W3C Recommendation), this Submission offers SWSL as an alternative to OWL and then uses it to define the semantics of SWSO. Although OWL-S and SWSO share many of the same concepts, they do not use the same URIs for them.
SWSO's expressivity exceeds conventional process calculi with
effects, which address global state.
SWSF will be brought to the attention of the Semantic Web Services Interest Group and to the Semantic Web Interest Group. SWSL, which was discussed as a candidate technology at the W3C Workshop on Rule Languages for Interoperability, will be one of several inputs to any W3C Rules Working Group. (Note that a draft charter for such a group is currently being developed.) SWSL, with a particular set of layers, bears a strong resemblance to the SWRL and SWRL-FOL languages, which were presented to the rules Workshop.
The fact that submitters Lucent and Hewlett-Packard have indicated that, at least at this time, they will not offer patent licenses according to the W3C Royalty-Free requirements, will have to be considered more carefully if any of this Submission is to be the basis for Recommendation Track work.