Bootstrap

Bootstrap is a open-source collection of tools for creating browser sites and applications.

Free Open Source Self-Hosted JavaScript HTML5 Boilerplate

Foundation

Foundation is an easy to use, powerful, and flexible framework for building rapid prototypes and production code on any kind of device.

Free Open Source Web

Semantic UI

Semantic empowers designers and developers by creating a shared vocabulary for UI.

Free Open Source Web

UIKit

A lightweight and modular front-end framework for developing fast and powerful web interfaces. ui framework full HTML / CSS, javascript component , form, theme , dropdown , responsive ... More full than bootstrap or foundation

Free Open Source Web

Materialize

Materialize is a modern responsive CSS framework based on Material Design by Google

Free Open Source Web

Skeleton

Skeleton is a small collection of CSS & JS files that can help you rapidly develop sites that look beautiful at any size, be it a 17" laptop screen or an iPhone.

Free Open Source Web

Purecss

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

Free Open Source Web

GroundworkCSS

GroundworkCSS is a 100% free and open source responsive HTML5, CSS and JavaScript Framework.

Free Open Source Web Self-Hosted

Spectre.css

Lightweight, responsive and modern CSS framework for faster and extensible development.

Free Open Source Web Self-Hosted

Material Design Lite

Google's front-end web framework for building sites to the Material Design specification.

Free Open Source Web GitHub

Picnic CSS

Unpack your meal and get coding. An invasive CSS library to get your style started.

Free Open Source Self-Hosted CSS

Blaze CSS

Open source modular CSS framework providing great structure for building websites quickly.

Free Open Source Mac OS X Windows Linux Self-Hosted

yeti.css

yeti.css is a pattern library consisting of lightweight, reusable modules. It has been built to reflect &yet's visual and branding guidelines.

Free Open Source Mac OS X Windows Linux Self-Hosted

960 Grid System

The 960 Grid System is an effort to streamline web development workflow by providing commonly used dimensions, based on a width of 960 pixels. There are two variants: 12...

Free Open Source Mac OS X Windows Linux BSD Web

The Goldilocks Approach

The Goldilocks Approach to Responsive Web Design - A good starting point for design that takes device resolution out of the equation.

Free Open Source Web

Element UI

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

Free Open Source Web Self-Hosted JavaScript Vue.js CSS

Kube Web Framework

Kube is one of the world's most advanced and flexible frameworks. Kube helps you spend less time on routine tasks and more time creating amazing products. Focus on...

Free Open Source Web

The Semantic Grid System

Set column and gutter widths, choose the number of columns, and switch between pixels and percentages. All without any .grid_x classes in your markup. Oh, and did we...

Free Open Source Web

Basis

Clean code development ====================== The Basis classes have prefix. And code style is BEM (MindBemding) and using Stylus. You can use it as CSS framework or...

Free Open Source Self-Hosted