From the Quest3D site:

Version 4.0 of Quest3D® is now available from Quest3D resellers and the Quest3D website.

With the release of Quest3D 4.0, Act-3D™ B.V. lifts its flagship to an even higher quality level of real-time 3D application development. New functionality contains real-time support for COLLADA, Newton Game Dynamics, Advanced Weather Simulation, 3D GUI Support and a fully Object-Oriented development model.

The new release is a giant leap forward in real-time 3D software development. High-end 3D software projects, such as 3D architecture visualizations, product and design presentations games and training simulators benefit from the newly supported technologies in Quest3D.