HeadlessX

Dropdowns, modals, tabs, accordions, all the interactive patterns you'd otherwise build from scratch, but with zero CSS opinions. MIT license, TypeScript. The 'headless' pattern means you get the behavior (keyboard navigation, ARIA attributes, focus management) and you bring the styles. Works with Tailwind, CSS Modules, styled-components, whatever.

Fully free. No paid tier, no hosted version. Install the package and use the components.

Solo through large teams: free at every scale. Headless UI libraries save the most time for teams with custom design systems; you get accessibility compliance without fighting pre-styled components.

The catch: is small for a component library. Radix UI (headless primitives by the Vercel/shadcn ecosystem) has and a much larger community. Headless UI by Tailwind Labs is another established option. HeadlessX is emerging and the component coverage may not match the established players. Check that it has the specific components you need before committing; an incomplete headless library means you're mixing sources or building the gaps yourself.