Sesame is an open source framework for storage, inferencing and querying of RDF data.
It 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.
Originally, it was developed by Aduna (then known as Aidministrator) as a research prototype for the EU research project On-To-Knowledge. Now, it is further developed and maintained by Aduna in cooperation with NLnet Foundation, developers from Ontotext, and a number of volunteer developers who contribute ideas, bug reports and fixes.