LESS proved to be an extremely valuable tool for us. While it was originally created in Ruby, we used LessPHP for the web application, and Less.js for our marketing site. Less offers many great extensions to vanilla CSS, including variables, mixins, and operations. This is what the LESS syntax looks like:
Here are some of the especially useful mixins that we put together:
Jekyll and Git
For our marketing site, we decided to use Jekyll rather than a full-blown content management system. It works terrifically for our environment where coders are maintaining the site. We push to our Git repository, which compiles the site in Jekyll and Less.js, then uploads it to our web servers. Take a look at the Less.js - Jekyll plugin we wrote, that compiles our Less for us.