It's using CSS animations.

  animation: spin 2s infinite linear;

For me the spinning wobbles on Chrome 23.0.1271.97 and doesn't work at all on IE9 despite the site banner claiming IE7 support?

There's a disclaimer about lack of support for css3 animations in IE7-IE9 further down the page

I think that the refresh icon is designed off-center causing it to spin off of its axis.

Have to say, the symbol for spinner icon is poor choice. It doesn't look good when animated like that; typically the individual dots grow/shrink sequentially (impossible to implement in CSS as long as the icon is a single element).

It may be my browser, but they look pretty naff.

For some reason the website represents them in true 1998 fashion using such a tiny font size, but they actually look very nice in bigger sizes. (Especially on HiDPI display!)