RDF/XML

RDF/XML is a syntax, defined by the W3C, to express (i.e. serialize) an RDF graph as an XML document. RDF/XML is sometimes misleadingly called simply RDF because it was introduced among the other W3C specifications defining RDF and it was historically the first W3C standard RDF serialization format.

RDF/XML is the primary exchange syntax for OWL 2, and must be supported by all OWL 2 tools.