Foundation is the most advanced responsive front-end framework in the world. Quickly go from prototype to production, building sites or apps that work on any kind of device with Foundation. Includes a fully customizable, responsive grid, a large library of Sass mixins, commonly used JavaScript plugins, and full accessibility support. Foundation has three kinds of tests: JavaScript, Sass, and visual regression.
https://foundation.zurb.com
https://github.com/zurb/foundation-sites