Polymer is a library that uses the latest web technologies to let you create custom HTML elements. Build anything from a button to a complete application as an encapsulated, reusable element that works across desktop and mobile.

Leaf (CSS Framework) is described as 'A CSS framework based on Google's material design' and is a CSS Framework in the development category. There are more than 50 alternatives to Leaf (CSS Framework) for a variety of platforms, including Web-based, Self-Hosted, Mac, Windows and Linux apps. The best Leaf (CSS Framework) alternative is Bootstrap, which is both free and Open Source. Other great apps like Leaf (CSS Framework) are Tailwind CSS, Semantic UI, Foundation and Material UI.
Polymer is a library that uses the latest web technologies to let you create custom HTML elements. Build anything from a button to a complete application as an encapsulated, reusable element that works across desktop and mobile.

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 rock-solid default for HTML5 awesome. HTML5 Boilerplate is the professional badass's base HTML/CSS/JS template for a fast, robust and future-proof site.
Front-end framework with a built-in dark mode and full customizability using CSS variables; great for building dashboards and tools.
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.
Stylify is a library that generates utility-first CSS dynamically based on what you write. Write HTML. Get CSS 🚀.




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.

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.