E-mail
 | Semantic Web information storage and retrieval systems. |
AllegroGraph
AllegroGraph RDFStore is a modern, high-performance, persistent RDF graph database. AllegroGraph uses disk-based storage, enabling it to scale to billions of triples while maintaining superior performance. AllegroGraph supports SPARQL, RDFS++, and Prolog reasoning from Java applications.
IBM Web Ontology Manager
A Web-based system for managing Web Ontology Language (OWL) ontologies available from IBM alphaWorks.
Kowari Metastore
Kowari is an Open Source, massively scalable, transaction-safe, purpose-built database for the storage, retrieval and analysis of metadata. Kowari is written in Java and licensed under the Mozilla Public License. Kowari supports Resource Description Framework (RDF) and Web Ontology Language (OWL) metadata.
Neo4j
Neo4j is a graph database. It is an open source, embedded, disk-based, fully transactional Java persistence engine that stores data structured in graphs rather than in tables. A graph (mathematical lingo for a network) is a flexible data structure that allows a more agile and rapid style of development. Neo4j can be turned into a SAIL compliant SPARQL endpoint (see http://components.neo4j.org/neo-rdf/), but translates SPARQL queries into actual Graph Traversals and stores the Triples as a connected graph.
Mulgara
Mulgara is a scalable RDF database written entirely in Java (open source).
Oracle
Oracle started support for RDF/RDFS/OWL in 10g and continues to improve upon it in Oracle Spatial 11g
OWLIM Semantic Repository
A high-performance semantic repository developed in Java. It is packaged as a Storage and Inference Layer (SAIL) for the Sesame RDF framework. OWLIM is based on TRREE – a native RDF database and rule-entailment engine.
Sesame
Sesame is an open source framework for storage, inferencing and querying of RDF data.