While we kind of like Less' approach to CSS, we were not thrilled with the performance and also found it not really enough for serious development.

We opensourced our attempt at CSS generation in a java environment.

The website is a little outdated http://dynamic-style-sheets.org/dss-website/index.jsp but might give a rough overview. The SVN is more up-to-date ( http://opensaga.org/svn/opensaga-dynamic-stylesheets/trunk/ )

In addition to rule nesting and mixings, variables, expressions, etc, DSS allows user-defined functions to be written. Some come with it, including a system do imagemagick or so like processing of images in the CSS.

It's a funny little thing that kind of just wanted to be written that way.