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

Kube Web Framework is described as 'Free CSS/JS advanced and flexible framework' and is a CSS Framework in the development category. There are more than 50 alternatives to Kube Web Framework, not only websites but also apps for a variety of platforms, including Self-Hosted, Mac, Windows and Linux apps. The best Kube Web Framework alternative is Bootstrap, which is both free and Open Source. Other great sites and apps similar to Kube Web Framework are Tailwind CSS, Semantic UI, Foundation and UIkit.
CSS-in-JS with build time generated styles, RSC compatible, multi-variant support, and best-in-class developer experience.

jQuery UI is an open source library of interface components — interactions, full-featured widgets, and animation effects — based on the stellar jQuery javascript library . Each component is built according to jQuery's event-driven architecture (find something, manipulate...


A set of beautifully-designed, accessible components and a code distribution platform. Works with your favorite frameworks. Open source. Open code.

Front-end framework with a built-in dark mode and full customizability using CSS variables; great for building dashboards and tools.
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.
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.



Flat UI Pro is made on the basis of Twitter Bootstrap in a stunning flat-style, and the kit also includes a PSD version for designers. Flat UI Pro contains a huge number of basic components, icons and glyphs.
GroundworkCSS is a 100% free and open source responsive HTML5, CSS and JavaScript Framework.