Open Source CSS Projects
Discover 16 open source CSS repositories from GitHub, each with an analysis of what it does, key features, use cases and alternatives. CSS projects here are most often combined with Web Development, Frontend and JavaScript. Last updated October 3, 2026.
16 repositories · updated October 3, 2026
html5-boilerplate: Start Fast, Adaptable Websites
HTML5 Boilerplate is a framework-independent front-end starter for building fast, adaptable websites and web apps. It provides a considered HTML, CSS, and project setup for developers who want a practical baseline without adopting a particular framework.
Style Observer: Run JavaScript When CSS Properties Change
Style Observer is a robust, production-ready JavaScript library designed to detect and respond to changes in any CSS property. It allows developers to run custom JavaScript code when a CSS property changes, offering a powerful way to create dynamic and reactive web interfaces. The library handles browser inconsistencies and provides a lightweight, dependency-free solution for observing styles.
cssql: Compile SQL-Like Stylesheets to CSS
CSSQL is an experimental language that models CSS selectors as tables and uses SQL-like commands to build and combine styles. Its Haskell transpiler converts CSSQL files into CSS, with a Node.js package for JavaScript projects.
tailwindcss: Build Interfaces with Utility-First CSS
Tailwind CSS is a utility-first CSS framework for building custom user interfaces. It suits developers who want to compose designs directly from utility classes and tailor styles to their projects.