Gravitator 2 is a sequel to the original Gravitator program. It integrates gravity and elastic collision simulation along with a solid 3D viewer. You can create many of the objects at once and make changes by using the Body Edit window. It even has a musical collision mode that causes the objects to strike chords according to mass. The menu bar and onscreen tools provide numerous options for creating the atmosphere of your choice. For more information, including on updates, please read the documentation or visit the home page.