Susy

Susy: un-obtrusive grid system for designers, built on Compass and Sass

Bootstrap

Simple and flexible HTML, CSS, and JS for popular UI components and interactions

Element, a Vue 2.0 based component library for developers, designers and product managers.

The most advanced responsive front-end framework in the world

Bootstrap Admin Templates on steroids! Collection of premium bootstrap admin templates.

Responsive HTML5, CSS and JavaScript Framework

Material Design Lite Components in HTML/CSS/JS

Thousands of fonts, icons, graphics, templates, & interfaces

Lightweight and beautiful library. Unpack your meal and start coding.

A set of small, responsive CSS modules that you can use in every web project.

A UI Component library implemented using a set of specifications designed around natural language

Spectre is a web application to diff screenshots.

A lightweight and modular front-end framework for developing fast and powerful web interfaces