Processing CSS

Regardless of whether or not your code has pre-processing steps, post-processing steps, or both, it's best to use fast tools that other tools can easily consume via stdout.

An asset pipeline for CSS can be constructed entirely this way.

It's useful to have a tool that can watch for changes on one or more files and execute commands (e.g. one-or-more compilation steps) when there are changes.

catw is one such tool.