ImageOptim - Faster web pages and apps.
Sass - Syntatically Awesome Style Sheets
Node.js - Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications
PostCSS - 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.
Ruby on Rails - Ruby on Rails is an open source full-stack web application framework for the Ruby programming...
Stylus - EXPRESSIVE, DYNAMIC, ROBUST CSS