SPARQL is a query language for pattern matching against RDF graphs. The syntax resembles SQL, making for a friendly learning curve, but SPARQL is far more powerful, enabling queries spanning multiple disparate (local or remote) data sources containing heterogeneous semistructured data.
There is a Drupal 7 port underway. This is a different take on the module which only includes the core SPARQL API functionality. This project also include the SPARQL registry module and the SPARQL endpoint module.
The SPARQL module requires the RDF Extensions module.
This is a module that enables the use of SPARQL queries with the RDF API for Drupal 6.x. For more information, read the introductory posting or watch the demo video. Be sure to subscribe to the Semantic Web group on groups.drupal.org to keep up with the latest happenings.