| AbstractCompiler | Base class for CSS Preprocessor. Provides basic configuration, Service Manager Factory Interface and compile method. |
| Less | Wrapper class for Less CSS preprocessor (http://lesscss.org/) |
| Sass | Wrapper class for Sass CSS preprocessor (http://sass-lang.com/) |
| Stylus | Wrapper class for Stylus CSS preprocessor (http://learnboost.github.io/stylus/) |
| UpdateListener | Event listener to update CSS files |