Ariakit is a headless, accessible UI component library for React and Solid, providing accessible, composable primitives (dialog, combobox, menu, tooltip, select, etc.) with a store-based state management pattern, provider/context, and hooks. It also includes a styled UI layer (Ariakit UI) with CSS variants. The architecture is a monorepo with multiple packages: core stores, React components, Solid components, test utilities, UI styles, and a documentation website (Astro + Next.js). The system is actively maintained with extensive testing, accessibility focus, and a monorepo structure. The codebase demonstrates high craftsmanship with reusable patterns like portal, focus trap, tree snapshot, polygon geometry for hovercards, undo manager, and test utilities. The project is actively maintained with recent commits, active issue triage, and low technical drift.