Radix UI, an open-source headless UI component library launched by Modulz in November 2020, has become a prominent choice for frontend developers seeking flexibility and accessibility in building design systems, websites, and applications. The library is notable for its unstyled components, allowing developers to use their preferred styling solutions like Tailwind CSS, and offers features such as Radix Primitives, Radix Colors, and Radix Themes, which provide customizable and accessible components. Used by companies such as Vercel, Supabase, and Linear, Radix UI supports server-side rendering and incremental adoption, making it suitable for both personal and large-scale projects. Despite its advantages, Radix UI's relatively limited component library and fixed icon dimensions, along with the need for developers to define styles from scratch, can present challenges. Nevertheless, its popularity is growing as a versatile tool for modern application development, often compared to other headless UI libraries like Headless UI by Tailwind CSS and React Aria.