Here’s the sales blurb….

Quest3D is a very flexible authoring environment for real-time 3D applications. It is packed with a huge set of features, very good support and very attractive license conditions. The edit-while-executing and graphical nature of Quest3D makes it one of the most intuitive tools to work with. Quest3D is used by hobbyists, educational institutions and big name companies. Projects include anything from small freeware games to huge industrial virtual reality setups.
Sounds Good. I’d like to check out the demo and see how it goes. It is quite pricey though.