OWL-S is an

ontology In metaphysics, ontology is the philosophical study of being, as well as related concepts such as existence, becoming, and reality. Ontology addresses questions like how entities are grouped into categories and which of these entities exis ...

built on top of Web Ontology Language (OWL) by the

DARPA The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Adv ...

DAML program. It replaces the former

DAML-S The DARPA agent markup language for services (DAML-S) is a semantic markup language for describing web services and related ontologies. DAML-S is built on top of DAML+OIL. DAML-S has been superseded by OWL-S OWL-S is an ontology built on top of W ...

ontology. "OWL-S is an ontology, within the OWL-based framework of the Semantic Web, for describing

Semantic Web Services A semantic web service, like conventional web services, is the server end of a client–server system for machine-to-machine interaction via the World Wide Web. Semantic services are a component of the semantic web because they use markup which m ...

. It will enable users and software agents to automatically discover, invoke, compose, and monitor Web resources offering services, under specified constraints."DAML Services
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The OWL-S Ontology

Development of OWL-S aims to enable the following tasks: * Automatic Web service discovery: with the development of the Semantic Web, many Web Services will be available on the Web, performing the most various tasks. OWL-S will help software agents to discover the Web Service that would fulfill a specific need within some quality constraints, without the need for human intervention. * Automatic Web service invocation: generally, it is necessary to write a specific program to invoke a Web Service, using its

WSDL The Web Services Description Language (WSDL ) is an XML-based interface description language that is used for describing the functionality offered by a web service. The acronym is also used for any specific WSDL description of a web service (also ...

description. OWL-S will open the possibility for a software agent to automatically read the description of the Web Service's inputs and outputs and invoke the service. * Automatic Web service composition and interoperation: in a Web where many services are available, it should be possible to perform a complex task, involving the coordinated invocation of various Web Services, based solely on the high-level description of the objective. OWL-S will help in the composition and interoperation of the Services in a way that will enable the automatic execution of this tasks. The OWL-S ontology has three main parts: the ''service profile'', the ''process model'' and the ''grounding''. * The ''service profile'' is used to describe what the service does. This information is primary meant for human reading, and includes the service name and description, limitations on applicability and quality of service, publisher and contact information. * The ''process model'' describes how a client can interact with the service. This description includes the sets of inputs, outputs, pre-conditions and results of the service execution. * The ''service grounding'' specifies the details that a client needs to interact with the service, as communication protocols, message formats, port numbers, etc.

OWL-S and WSDL

OWL-S requires an additional description for a full specification of the grounding, the most commonly used being

. Although both languages target at different levels of specification, there is an intersection between them: * An OWL-S atomic process corresponds to a WSDL operation; * The inputs and outputs of an OWL-S atomic process correspond to WSDL messages; * The types of the inputs and outputs of an OWL-S atomic process correspond to WSDL abstract types.

References

{{reflist Markup languages Semantic Web Web services

The OWL-S Ontology

OWL-S and WSDL

See also

References