CSS-in-JS with build time generated styles, RSC compatible, multi-variant support, and best-in-class developer experience.

Halfmoon is described as 'Front-end framework with a built-in dark mode and full customizability using CSS variables; great for building dashboards and tools' and is a CSS Framework in the development category. There are more than 50 alternatives to Halfmoon for a variety of platforms, including Web-based, Self-Hosted, Mac, Windows and Linux apps. The best Halfmoon alternative is Bootstrap, which is both free and Open Source. Other great apps like Halfmoon are Tailwind CSS, Bulma, Semantic UI and Foundation.
CSS-in-JS with build time generated styles, RSC compatible, multi-variant support, and best-in-class developer experience.

Create beautiful, responsive & accessible web apps quickly with Vue or Nuxt. Nuxt UI is an open-source UI library of 100+ customizable components built with Tailwind CSS and Reka UI.




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. Skeleton is built on three core principles:
A set of beautifully-designed, accessible components and a code distribution platform. Works with your favorite frameworks. Open source. Open code.

A unified, HTML5-based user interface system for all popular mobile device platforms, built on the rock-solid jQuery and jQuery UI foundation. Its lightweight code is built with progressive enhancement, and has a flexible, easily themeable design.


Topcoat is a brand new open source CSS library designed to help developers build web apps with an emphasis on speed. It evolved from the Adobe design language developed for Brackets, Edge Reflow, and feedback from the PhoneGap app developer community.
Topcoat is the most popular Windows, Mac & Linux alternative to Halfmoon.
Eva Design System is a free and open-source, customizable design system. Available for Sketch with Mobile and Web component libraries.

Spectre.css is a lightweight, responsive and modern CSS framework for faster and extensible development.
This project's goal is to be able to create a fully accessible material design styled website using React Components and Sass.

Metro UI CSS a set of styles to create a site with an interface similar to Windows 8.
Little Widgets is a collection of beautifully designed HTML website widgets and popups. It’s coded, responsive, animated and ready to use on your website.



Simple. Robust. Responsive. Flexible.
Based on Flexbox (CSS Flexible Box Layout Module), Gridlex is a very simple css grid system to quickly create modern layouts and submodules.
