Vizard is a high-level toolkit for creating interactive virtual environments. It uses Python for scripting and, of course, OpenSceneGraph for rendering.
The power and ease of use of OSG has been instrumental in the success of this product. The friendly and knowledgeable community was very helpful as well.
Some of our customers include NASA, Boeing, Lockheed Martin, Pratt & Whitney, EADS, Disney, MIT, and Stanford University.
Here are a few screenshots of simulations made with Vizard. There are more on our website, including some videos as well.