As of December 2009 the above SVG animation only works properly in Opera 10.10. Google Chrome apparently cannot animate attributeName="d" correctly. FireFox 3.5 cannot animate anything, and even Gecko 1.9.3/FireFox 3.7 will not be able to render animateMotion. Animate motion moves the ball along a path. An alternate approach is to animate the attributeName="cx", a technique used in an accelerating ball animation. The above animation was redone with the animate attibuteName approach for use in Google Chrome.