Gravity
This object can animate HTML page elements using the laws of physics. It uses the Box2DWeb library to animate given page elements so they move, rotate and collide according to laws of physics. The gravity acceleration and direction is a configurable options. Given callback functions may be invoked when objects collide. Objects speed and rotation may be affected when the user drags them using the mouse pointer. Each page element be made static or animated. Animated page elements may include the respective children elements. The elements' friction and density properties can also be configured.