Open source. Open possibilities.

Franken UI (franken-ui/ui) is described as an HTML-first UI component library built on UIkit 3, extended with LitElement and inspired by shadcn/ui. Its README now only announces a move to 0build, so documentation lives elsewhere.

Bulma is a modern, Flexbox-based CSS framework distributed as a single CSS file with no JavaScript. It offers Sass sources for variable customization and works with any frontend stack.

A collection of bouncing DVD logo implementations across a wide variety of programming languages and platforms.

Priceline Design System is Priceline.com's open-source UI component library and design standard. It aims to unify interface patterns, speed design and development, and promote accessibility, internationalization, and responsive web design. It ships as the npm package pcln-design-system with Storybook docs and an MIT license.

Spruce CSS is an open-source, lightweight Sass-based CSS design system and framework offering variables, mixins, functions, few utility classes and CSS custom property theming with dark mode.

Helsinki Design System (HDS) is an open-source design system from the City of Helsinki, offering accessible React components, CSS styles and design tokens, alongside documentation and design resources.

GitHub Dark is a userstyle project that applies a dark theme to GitHub, reducing eye strain during coding sessions. It includes syntax highlighting themes for GitHub, CodeMirror, and Jupyter, and is designed to be used with browser extensions like Stylus.

Material Design for Bootstrap is a free UI kit offering 700+ components, themes, and templates for building responsive, mobile-first websites. Available for jQuery, Angular, React, and Vue under MIT license.

A collection of 120 plain-text DESIGN.md brand design specifications reverse engineered from live production sites, letting AI coding agents generate on-brand UI. Each brand includes real colors, typography, components and guardrails plus a self-contained preview.html.

TW Elements is an MIT-licensed component library for Tailwind CSS, offering 500+ interactive UI components and 117+ design blocks with dark mode support, theming options, and quick installation for personal and commercial use.

Anime.js is a fast, lightweight JavaScript animation library with a powerful API for animating CSS properties, SVG, DOM attributes, and JavaScript objects.

A curated directory of CSS frameworks organized by category, including base resets, classless frameworks, lightweight options, general-purpose frameworks, Material Design, utility-based, specialized, and stalled projects.

Flowbite is an open-source UI component library built on Tailwind CSS, offering interactive components like modals, dropdowns and datepickers driven by data attributes, with vanilla JS APIs, TypeScript types, RTL support and bindings for React, Vue, Svelte and Angular.

Font Awesome is a widely used icon library and toolkit providing SVG, font, and CSS resources for designers and developers. Version 7 is the current release.

designlang is a Playwright-based CLI that reads a website's live DOM and extracts its design system: DTCG tokens, Tailwind config, Figma variables, shadcn theme, component anatomy, motion tokens, brand voice, WCAG contrast audits, and multi-platform emitters, plus MCP server and Chrome extension.

A web-based gallery designed to showcase pixel art creations.

Tabler is a free, MIT-licensed HTML dashboard UI kit built on Bootstrap 5, offering ready-made layouts, components and 120+ demo pages for admin panels, dashboards and web apps, with dark mode, RTL stylesheets, Sass sources and TypeScript types.

A curated English-language collection of bookmarks, resources, articles, and tools about design systems for developers, covering design tools, design tokens, pattern libraries, component testing, books, and talks.

Metis is a free MIT-licensed Bootstrap 5 admin dashboard template built with Alpine.js, Vite and SCSS. It ships responsive dashboard, user/product/order management, calendar, messages, reports, settings, auth and error pages, plus dark/light themes and a self-hosted asset setup.

Oruga is a lightweight Vue.js 3 UI component library with no CSS framework dependency. It provides customizable components, tree-shaking, themes, and class-mapping configuration for integrating Tailwind, Bulma, Bootstrap, or custom styles.