As one of the first scalable RDF Semantic Stores, Mulgara has had a very capable query language called TQL. The Mulgara project added programmatic support for SPARQL earlier this year, but the 2.0.6. release has just added support for the SPARQL Protocol with results retrievable as either JSON or XML. It also now does auto-detection between SPARQL and TQL through the web user interface. Additional new features include faster data loads, improved backup and restore functionality, an HTTP endpoint for TQL as well as some important bug fixes. More information can be found here.