i have been a heavy user of less, the dynamic css processor, for sometime now. it has been an invaluable time-saving and creatively-inspiring tool in my front-end workflow. with less.js, it is easier than ever to get rolling. since less has now been ported to javascript, it can be rendered in the browser - no need to install the gem and watch/render the css file. just include the script and point at your .less file and you are all set =>
<link rel="stylesheet/less" href="/css/main.less" type="text/css">
<script src="/js/less.js" type="text/javascript">