OSF-Drupal is premised on structured data. It uses the RDF (Resource Description Framework) data model as its canonical structured data form. External formats are converted to RDF. We are also able to export internal RDF into a number (and growing) of wild data formats.
RDF has manifest advantages as the canonical form for structured data. RDF is simultaneously a framework, data model and basis for building more complex vocabularies. It is both simple and complex at the same time. Rather than repeat here its various advantages, we recommend the Advantages and Myths of RDF document as a great place to learn more.
The OSF-Drupal RDF data (and other functions) is presently managed by the OpenLink's Virtuoso software. Virtuoso is a cross-platform ‘universal server’ for SQL, XML, and RDF data, including data management, that also includes a powerful virtual database engine, native hosting of existing applications, Web services deployment platform, Web application server, and bridges to numerous existing programming languages.
We mostly use the RDF, SPARQL and inferencing capabilities of Virtuoso. In our tests, it is the best performing RDF datastore available. We utilize the open source version of Virtuoso.