ASTRA is a set of software tools for mediated interpersonal awareness, addressing the need to stay in touch with family and friends or the need to be reassured regarding their well-being. The software provides a service oriented architecture, user tools, and applications that support communities to appropriate Pervasive Awareness applications.
4store is an efficient, scalable, and stable RDF database. It was developed to underpin Semantic Web applications. It has been providing a base platform for these applications for around 3 years. It has successfully held and run queries over databases of 15GT, supporting a Web application used by hundreds of thousands of people.
Sesame is an Open Source RDF Schema-based repository and querying facility. It is a scalable, modular architecture for persistent storage and querying of RDF and RDF Schema. It supports two query languages (SPARQL and SeRQL), and can use main memory or PostgreSQL, MySQL and Oracle 9i databases for storage.
Redland is a set of C libraries providing a high-level API for the Resource Description Framework (RDF), allowing it to be stored, parsed, serialized, queried, and manipulated. It has an object-based, modular design and comes with detailed reference documentation and examples. Redland supports all RDF vocabularies such as FOAF, RSS 1.0, Dublin Core, DOAP, and OWL, the query languages SPARQL and RDQL, and all RDF syntaxes including Turtle, RDF/XML, RDF/JSON, RSS, Atom, RDFa, and GRDDL.
Bitsy is a small, fast, embeddable, durable in-memory graph database that implements the Blueprints API. It is an ACID database that recovers cleanly from power failures and crashes. Designed for multi-threaded OLTP applications, Bitsy implements optimistic concurrency control and stores data in human-readable JSON-encoded text files. Common management tasks such as online backups can be done over JMX. The speed and simplicity of Bitsy relies on three design principles: No Seek, No Socket, NoSQL.
Rasqal is a C library for querying RDF graphs, supporting the SPARQL, RDQL, and LAQRS languages. It provides APIs for creating a query and parsing query syntax. It features pluggable triple-stores and matching interfaces, query engines for executing the queries, an API for manipulating results as bindings, and multiple ways to format the results to XML, CSV, TSV, and JSON. It uses the Raptor RDF parser to return triples from RDF content, and can alternatively work with the Redland RDF library's persistent triple stores. It is portable across many POSIX systems.