I am happy to share the upgrade of my (commercial) product Flow partially made with OSC
Flow is an integrated environment providing a solid template built with Cubase and Vienna Ensemble Pro plus a controller application built of course with Open Stage Control.
From the app you can select tracks, enable instruments, switch articulations, control microphones and other controllers, search instruments or articulations... and more and more
Actually it offers ready to use integration with Spitfire Audio and Orchestral Tools libraries, more will come, but in the end it is an open project so one can use it as a start to add all the libraries he wants.
You can find more info here
or check this introduction video