Usually when using AJAX on your website you use an image spinner while retrieving content. But, what if you can create a spin image without using an actually image? Spin.js can do this job for you. This spinner has no images and no external CSS, no dependencies (jQuery is supported but not required), is highly configurable, resolution independent, uses VML as fallback in old IE browsers, uses @keyframe animations and works in all major browsers including IE6.
Spin.js is created under MIT license and has been tested successfully on Chrome, Safari 3.2+, FF 3.5+, IE (6-9), Opera 10.6+, Mobile Safari (iOS 3.1+) and Android 2.3+. On the official spin.js there is a nice tool for configuring your spinner and some basic configuration documentation.
Spin.js spinner preview