Sesame is an open source RDF database with support for RDF Schema inferencing and querying.

Sesame has been designed with flexibility in mind. It can be deployed on top of a variety of storage systems (relational databases, in-memory, filesystems, keyword indexers, etc.), and offers a large scala of tools to developers to leverage the power of RDF and RDF Schema, such as a flexible access API, which supports both local and remote (through HTTP or RMI) access, and several query languages, of which SeRQL is the most powerful one.

URL: http://www.openrdf.org/
Licence: LGPL