1. Syntatically Awesome Style Sheets

  2. Less extends CSS with dynamic behavior such as variables, mixins, operations and functions. Less runs on both the server-side (with Node. js and Rhino) or client-side (modern browsers only).

  3. Compass provides tools to build digital call scripts.

  4. Increase code readability. Add vendor prefixes to CSS rules using values from Can I Use. Autoprefixer will use the data based on current browser popularity and property support to apply prefixes for you.

  5. Stylus Studio is a fully featured and comprehensive suite for editing and developing in XML.

  6. Bourbon - A simple and lightweight mixin library for Sass / CSS.

  7. Plugin to remove unused css.