This document discusses several database technologies for the semantic web including triplestores, Sesame, SeSQL, Virtuoso, Jena, R2RQ, and large triplestores. Triplestores store RDF data as subject-predicate-object triples and support adding, removing, and querying triples. Sesame is an open-source framework for querying, inferencing and analyzing RDF data that can use several database backends. SeSQL is Sesame's RDF query language. Virtuoso is an object-relational SQL database with a built-in web server that supports SPARQL. Jena is an RDF API from HP Labs for reading, writing and querying RDF with OWL support