RDF (Resource Description Framework) is a language for data description that is the basis of the Semantic Web. RDF imagines data as a graph in which individuals (nodes) are related to each other by way of predicates (edges). This graph can be interrogated using the SPARQL Protocol and RDF Query Language, which allows the user to specify combinations of required and optional graph patterns. This tutorial will introduce SPARQL as a means to query local and remote RDF data, with concrete examples provided using the platform-independent ARQ toolkit. Query federation among multiple data sources will also be discussed, with concrete examples provided using SWObjects.
Luke McCarthy is a programmer who has been working on Semantic Web-related projects for five years, most recently as the lead developer of SADI (Semantic Automated Discovery and Integration), a framework for building Semantic Web Services.