Web

Esri's Calcite Design System for consistent ArcGIS experiences, offering a UI kit, icons, color schemes, and a web component library for mapping apps.

GE HealthCare's Ethos Design System (EDS, formerly Edison), shared design and code standards for clinical software, medical device screens, and digital brand touchpoints.

GitHub's open source design system, with Primer Product UI and Brand UI, Primitives design tokens, Octicons, and accessibility guidance for building GitHub.

GitLab's Pajamas Design System, with brand and product guidelines, design tokens, Tailwind utilities, and a Figma UI kit for building the GitLab product.

Material Design 3, Google's open source design system for adaptive, expressive products, with tokens, components, and implementations for Compose, Flutter, and the web.

The UK government's design system for public services, with research-backed styles, components, and patterns implemented in the open source GOV.UK Frontend package.

The City of Helsinki's open source design system, bringing guidelines, design assets, and component libraries together for a consistent, accessible digital city brand.

IBM's open source design system built on the IBM Design Language, with React and Web Components libraries, design kits, guidelines, and an active contributor community.

Ideagen's Helix design system for its governance and compliance software, whose component documentation now lives inside Figma rather than the legacy site.

Sirio, the design system of Italy's social security institute INPS, uniting brand guidelines, product rules, writing guidance, and UI kits for citizen services.

Kajabi's Sage design system, the source of truth for its creator platform, with components written for both Rails and React plus Sass-based foundations.

Kiwi.com's open source Orbit design system for travel products, with React components, design tokens, Tailwind presets, and a free public Figma library.

Lemon Squeezy's open source Wedges library, a growing set of React components built on Radix primitives and Tailwind CSS, with a matching Figma kit.

Duet, the design system behind LocalTapiola and Turva digital products, offering web components, a CSS framework, and design tokens with accessibility built in.

Maersk Technology's design language, providing styles, tokens, themes, layouts, web components, icons, and content guidelines for consistent logistics products.

Meta's open source Astryx design system, a fully customizable, agent-ready React component library built on React 19 and StyleX, currently in beta.

Michelin's design system for digital products, with a Figma UI kit, tokens, icons, accessibility guidance, data visualization rules, and Angular, Blazor, and Svelte resources.

Microsoft's Fluent 2 design system for moving fluidly between design and code across web, iOS, Android, and Windows, with tokens, components, and AI guidance.

monday.com's Vibe design system, official React UI resources for building monday.com apps, documented in Storybook with foundations, theming, hooks, and an MCP server.

MongoDB's open source LeafyGreen design system and React UI kit, now in maintenance mode as new MongoDB products move to its successor, Via.

Morningstar's shared design language for investor experiences, covering foundations, voice and tone, a custom typeface, and a data visualization system.

Motorway's design system, The Highway Code, helping teams design and build consistent car-selling experiences with Figma libraries and React components.

Mozilla's Protocol design system for Mozilla and Firefox websites, providing a common design language, reusable coded components, and content and accessibility guidelines.

New York State's shared library of accessible web components, design tokens, and guidelines for agencies building mobile-friendly digital services.