CSS

CSS Object Model implemented in pure JavaScript.

Detailed CSS parser with syntax validator.

CSS parser with support for preprocessors.

A decent CSS parser.

CSSLint/parser-lib.

Plugin framework for CSS preprocessing in Node.js.

Transforming CSS with JS plugins.

Modern CSS for all browsers.

Backwards compatible with CSS, and the extra features it adds use existing CSS syntax.

Mature, stable, and powerful professional-grade CSS extension language.

Light-weight CSS preprocessor.

Expressive, robust, feature-rich CSS language built for NodeJs.

Expressive, robust, feature-rich CSS language built for NodeJs.

Expressive, robust, feature-rich CSS language built for NodeJs.

A lightweight (12k, not minified) but useful CSS framework with flexible Grid, Hero and more.

Modular and customizable Material Design UI components for the web.

Feature rich CSS framework for the new decade.

A set of common flexbox utilities focused on making your life easier and faster with nested flexboxes.

A utility-first CSS framework for rapid UI development.

You can find more frameworks at "awesome-css-frameworks"

Find and Reduce Similar & Duplicated CSS Scripts.

A tiny modern CSS reset.

Adds OpenType features—ligatures, kerning, and more—to Normalize.css.

A set of CSS rules that provide better cross-browser consistency in the default styling of HTML elements.

A Futuristic CSS Reset/Normalizer. That Redifines Instead Of Preserving.

A set of CSS rules that style with today’s best practices out-of-the-box.

Specialised stylesheet for removing user agent styles, style the web with your baseline.

by Guilherme Rv Coelho

by Dropbox

by Nicolas Gallagher

by Microsoft

A library to make creating CSS polyfills much easier.

Break free from CSS prefix hell.

A CSS position:sticky polyfill.

A JavaScript utility that emulates CSS3 pseudo-classes and attribute selectors in Internet Explorer 6-8.

Allows Internet Explorer to recognize and render various CSS3 box decoration properties.

Magic CSS extension for Chrome, Firefox and Edge.

A CSS bookmarklet that uses selectors to find bad markup, displaying ugly pink error messages in comic sans serif wherever you write bad HTML

One <div>. Many possibilities.

Convert xpath to css selector.