Open source. Open possibilities.

Chroma Chords is a tactile web audio widget for quickly generating and arranging chord progressions by vibe, genre, and mood, with theory analysis and MIDI/WAV export.

Official LottieFiles web player for Lottie (.json) and dotLottie (.lottie) animations, with a Rust + WASM core, Canvas2D/WebGL2/WebGPU backends, runtime theming, state machines, audio, worker rendering, and React, Vue, Svelte, Solid and Web Component SDKs.

Storybook is a frontend workshop for building, documenting, and testing UI components and pages in isolation. It supports many frameworks and offers addons for accessibility, documentation, and interactive development.

Numl is a deprecated UI design language, web-component library and runtime CSS framework for quickly building interfaces that follow a design system, loadable with a single JavaScript module and no bundler or config.

Happy DOM is a JavaScript implementation of a web browser's DOM without a graphical user interface, designed so browser-style code and component tests can run in runtimes like Node.js and Bun.

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.

Material Web (@material/web) is a library of web components implementing Google's Material 3 design system, for building accessible web apps. It ships from npm and can be loaded directly from a CDN. Note: the project is in maintenance mode pending new maintainers.

AgnosticUI Local (v2) is a CLI-based, framework-agnostic UI component library that copies component source, styles and tests directly into your project for React, Vue, Svelte or Lit, with 55 accessible components, CSS custom-property theming and AI prompt playbooks.