Web Services Description Language (WSDL) is a new specification to describe networked XML-based services. It provides a simple way for service providers to describe the basic format of requests to their systems regardless of the underlying protocol (such as Simple Object Access Protocol or XML) or encoding (such as Multipurpose Internet Messaging Extensions). WSDL is a key part of the effort of the Universal Description, Discovery and Integration (UDDI) initiative to provide directories and descriptions of such on-line services for electronic business. This article provides a brief background and technical introduction to WSDL. Knowledge of XML and XML Namespaces is required and some familiarity with XML Schemas and SOAP is useful.

The Resource Description Framework is the World Wide Web Consortium's official format for defining the metadata of XML objects. Conceptually, it is similar to Web Services Description Language, which is a collection of metadata about XML-based services. This article focuses on building a bridge between the two specifications. It provides an example of what a Web service description might look like as an RDF file. It then goes on to discuss how to take advantage of an RDF visualization tool to generate a graph of the WSDL data. Finally, it presents a portion of a possible RDF Schema for WSDL.