Protégé is supported by a strong community of academic, government, and corporate users, who use Protégé to build knowledge-based solutions in areas as diverse as biomedicine, e-commerce, and organizational modeling.
The OWL API is a Java API and reference implmentation for creating, manipulating and serialising OWL Ontologies.
OpenRDF Sesame is a de-facto standard framework for processing RDF data. This includes parsers, storage solutions (RDF databases a.ka.triplestores), reasoning and querying, using the SPARQL query language. It offers a flexible and easy to use Java API that can be connected to all leading RDF storage solutions.
Graphs are a powerful, flexible means of representing all kinds of linked data. Bigdata is an ultra high-performance graph database supporting the RDF data model, which provides a standards-based way of describing, interchanging, and querying graph data. Bigdata supports both the Sesame and Blueprints APIs.
Bigdata handles very Big Graphs. Bigdata scales to 50 billion edges on a single machine and will scale to even larger graphs with its horizontally-scaled architecture. Bigdata supports robust enterprise deployments with high up-time and QoS demands with its quorum-based high-availability (HA) architecture.
Bigdata is 100% open-source.
GraphDB™ (formerly OWLIM) is the world’s leading RDF Triplestore built on OWL (Ontology Web Language) standards. It stores your data in the form of atomic facts expressed as subjects, predicates and objects which have relationships to other facts. Ontotext offers three versions: GraphDB™ Lite, GraphDB™ Standard and GraphDB™ Enterprise.