The W3C RDF Data Access Working Group has published the last call working draft of SPARQL Protocol for RDF. "The RDF Query Language SPARQL expresses queries over RDF graphs. This document employs WSDL 2.0 to define a protocol for conveying those queries, as well as other operations, to an RDF query processing services and conveying the results of such queries and operations to the entity that requested them. This document also describes an RDF vocabulary for describing the capabilities and characteristics of RDF query processors."