Open source. Open possibilities.

Oat is an ultra-lightweight, zero-dependency semantic HTML/CSS/JS UI library (~10KB min+gz). It needs no framework or build step, styles semantic tags contextually without classes, and uses minimal JS WebComponents for dynamic parts.

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.

Vuetify is an MIT-licensed Vue UI component framework offering handcrafted, responsive components with theming, SASS customization, Vite tree-shaking and 42+ language support.

UI UX Pro Max is an open-source AI skill for Claude Code, Cursor, and other AI coding assistants. It provides design intelligence including 79 searchable UI styles, 192 industry-specific reasoning rules, 192 color palettes, 74 font pairings, and stack-specific UI/UX guidelines across 22 tech frameworks.

daisyUI is a free and open-source component library for Tailwind CSS. It offers pre-designed, customizable UI components that can be used directly in HTML. The project is popular and includes extensive documentation, a component gallery, and community support.