Astrum is a lightweight pattern library designed to be included with any web project. It's non-opinionated and doesn't expect you to write your markup or code in any particular way.
Build responsive, mobile-first projects on the web with the world's most popular front-end component library. Bootstrap is an open source toolkit for developing with HTML, CSS, and JS.
Build your design system faster now. And keep it from breaking later. Meet Ether, a modular base for any design system.
Fractal is a tool to help you build and document web component libraries, and then integrate them into your projects. Fractal can be run from the command line or integrated into your project via its API.
Foundation is a family of responsive front-end frameworks that make it easy to design beautiful responsive websites, apps and emails that look amazing on any device.