This was released on the 20th but has been updated today. They implement their RDF server on top of SQL databases and offer features like transactions, views, text mining and ontology maintenance. I think their web site is nicely put together. It uses the mysterious KAON CMS.
They've apparently been working on performance:
"For example, the server has been tested with an ontology of 100,000 concepts, 700,000 instances and 200,000 properties. Operations such as loading and changing the ontology now take only a couple of seconds.
The core of the engineering server forms an optimized database schema, and extensions of KAON API allowing bulk-loading of multiple objects in one call."