As of February 8th, 2012 the 3D transforms in this demo only work using Safari 5, Chrome 10+, the WebKit Nightly build, and Firefox 10+. Browsers without 3D Transforms just make a circular pattern. Not as fun :(
This slinky uses -webkit-transform: rotateY() and rotateX(); with some of the 3D settings: -webkit-transform-style: preserve3d; and -webkit-transform-perspective. It also uses -webkit-animation and -webkit-keyframe. Gecko browsers use their -moz equivalents of course. I have reduced the number of slinky segments temporarily so Firefox can process this demo.