I once payed for 3D RAD but found soon that its problem is inflexibility. It works with predefined objects, you can only use the objects that are included. More or less, with this limited set of objects you can only make variants of its demos. Thats why it probably didnt sell anymore and its programmer made it freeware. But since its freeware no one should complain. Anyway the free lite C version is way better and not limited to predefined objects.