Just paste your CSS into the input box, click “Convert,” and you get source code and a SVG Preview image. Easy!
Very useful for creating fallback images for older browsers to get the same appearance. Some browsers can just use the SVG images directly, but for others you can open the SVG in an image editor and save it as a PNG, GIF, or JPEG.
Full details are on the converter app’s page: http://www.kmhcreative.com/labs/css3-2-svg/