Open source. Open possibilities.

Panda is a universal, type-safe CSS-in-JS framework for design systems. It extracts styles at build time, outputs modern CSS with cascade layers and variables, supports recipes and variants, and works with most JS frameworks.

An MCP server providing expert design and marketing knowledge for AI agents, covering UI/UX, SEO, GEO, and platform-specific guidelines for web, iOS, Android, and macOS.

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.

Braid is SEEK Group's themeable design system, distributed as a React component library. It provides themes, BraidProvider, and components styled with Vanilla Extract, with setup guidance for sku-based projects.

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.

oh-my-design installs design system references and skills into AI coding agents. One command adds 440+ company design references, 28 skills, and 20 specialist roles to Claude Code, Codex, Cursor, and OpenCode. Produces a portable DESIGN.md with philosophy, tokens, and component contracts.

A lightweight, modular and customizable design system built with vanilla CSS, using CSS variables, mobile-first responsive principles and accessibility practices. It includes examples, design tokens, build and lint scripts, format conversion, and a CDN-ready combined CSS file.

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.

DesignMD is a CLI tool that extracts live design systems from any URL — colors, typography, spacing, breakpoints, and interaction states — and outputs a portable DESIGN.md file optimized for AI coding agents.

CompoMo (@ds-mo/ui) is a framework-agnostic Stencil.js web component library styled with TokoMo design tokens, shipping generated Angular, React and Vue adapters alongside an MCP metadata server.

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.

Tailgrids is an open-source React UI component library built with Tailwind CSS, offering 100+ production-ready copy-paste components plus UI blocks and templates, with TypeScript support, accessibility, dark mode and a CLI installer.

Chakra UI is an open-source React component system for building accessible web apps and SaaS products quickly. It ships installable component packages, supports Next.js RSC, and is MIT licensed.

Lightswind UI is an English-documented React component library distributed as source code via a CLI. It provides 160+ animated, accessible components and an MCP server for AI coding tools, with MIT-licensed core components and optional Pro content.

Codex is the design system for Wikimedia, offering Vue 3 and CSS components, design tokens, icons, and a VitePress documentation site. It supports internationalization and meets WCAG 2.1 AA accessibility standards.

Cloudscape Design System's React component library, open-sourced by AWS. Provides accessible, ready-made UI components and global styles for building large-scale web applications, with documentation on the Cloudscape website.

Skeleton is an adaptive design system built on Tailwind CSS. It provides turnkey components for popular web frameworks, along with documentation, a theme generator, and community channels.

Ark UI is a headless, unstyled component library from the Chakra UI team, offering 45+ accessible UI primitives built on Zag.js state machines with the same API across React, Solid, Vue and Svelte.

Carbon is IBM's open-source design system for products and experiences. This monorepo provides React and web component libraries, Sass styles, design tokens, icons, pictograms, and tooling for building consistent interfaces.

@alifd/next is Alibaba Fusion's configurable React component library for enterprise backend (mid/back-office) systems. It pairs with Fusion Design theme packages so designers and developers share one visual source, and supports npm or browser installs plus per-module imports.