Hi! The research branch of Virtuoso, version 7, has been released. They have gotten a lot of traction through the EU-funded LOD2 project, and from a performance viewpoint, Virtouso 7 looks amazing. I can't vouch for the stability though. However, since it has gone some months since the release, I really hope Virtuoso 7 could make it to jessie soon. That would also allow a lot of time to really put the thing to the test. Cheers, Kjetil