CSS

Adobe's design system behind its creative and document products, with shared foundations, tokens, and component implementations for React and Web Components.

Alaska Airlines' Auro design system, built around framework-agnostic web components, design tokens, and CSS guidelines shared across Alaska and Hawaiian brands.

The Swedish Public Employment Service's design system, with a Figma UI kit, design tokens, and Stencil web components usable from Angular, React, or plain HTML.

Aviva's digital standards hub and ION atomic design system, setting design, code, and accessibility expectations for Aviva websites, apps, and emails.

Biings' lightweight design system delivered as a single CSS file and SVG icon sprite, documenting foundations and core UI components for its products.

The U.S. Centers for Medicare & Medicaid Services' open source design system for Section 508 compliant, responsive sites, with themes for CMS.gov, HealthCare.gov, and Medicare.gov.

Denmark's free, open source common design system for building simple self-service solutions on borger.dk and Virk, with styles, components, and accessibility guidance.

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.

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.

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.

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.

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

Nordhealth's Nord Design System, production-grade web components, design tokens, Tailwind CSS support, and Figma toolkit behind its healthcare software products.

Tractie, Dutch Railways' design system for internal employee applications, with fundamentals, components, patterns, and support for web, Mendix, and Android developers.

The NSW Government's open source digital design system, a toolkit of core styles, components, templates, and guidance for distinctly NSW digital services.

The Government of Ontario's design and coding standards for building public products, with documented components, release notes, and web component packages.

Orange's toolkit of design guidelines and interface components for web, Android, iOS, and Flutter, with Figma UI kits and open source development libraries.

Power Home Remodeling's open source Playbook design system, with matching components for React, Ruby on Rails, and Swift plus Figma resources and theming.

Red Hat's open source PatternFly design system for enterprise products, with HTML and React implementations, charts, design tokens, and extensive usage guidance.

Salesforce's Lightning Design System, now SLDS 2, offering styling hooks, utility classes, icons, accessibility rules, and AI design guidance for building on Salesforce.

Tailwind CSS, the utility-first CSS framework for building any design directly in markup, with a configurable theme that acts as a shared design token layer.