RDF, Jena, SparQL and the "Semantic Web"

ABSTRACT The Resource Description Format (RDF) is used to represent information modeled as a "graph": a set of individual objects, along with a set of connections among those objects. In that role, RDF is one of the pillars of the so-called Semantic Web. This paper describes how RDF-XML is used to serialize information represented using graphs, how RDF graphs can be read and written by using the Jena software package, and how distributed graphs can be queried using the SparQL query language. It includes examples showing how SparQL can be used to query data (such as the Gene Ontology) that is structured in hierarchies, and how SparQL queries can be submitted through SparQL "endpoints." It does not, however, delve into inference or the Web Ontology Language (OWL), but should provide a foundation for understanding those topics