When the acquisition of Radix's parent company stalled the library's development, its original creators walked to MUI and rebuilt it from scratch as Base UI. Not a code fork - a people fork, and in 2026 the ecosystem's most important default changed to follow them.
A headless React component library built from scratch on Floating UI, with an API designed for unstyled, highly customizable components. It shares Radix's accessibility-first philosophy and much of its API shape, but is an independent implementation - no Radix code, no Radix license concerns, and native support for modern React patterns including server components.
Radix Primitives, launched by the Montreal-based company Modulz in 2020, became the standard toolkit for accessible React UI components - the foundation under shadcn/ui, the most popular component collection in the React world. In June 2022 Modulz was acquired by WorkOS, the authentication company, which kept the project open-source but slowed its development to a trickle: the 2023 release count was a fraction of prior years, and the roadmap the community cared about was subsumed by WorkOS's commercial priorities. The original creators - Jenna Smith, Colm Tuite, and James Nelson - left and were hired by MUI, the company behind Material UI.
In February 2024, MUI announced it would build 'Base UI', an accessible headless component library 'from the creators of Radix, Floating UI, and Material UI' - effectively Radix rebuilt by its own authors, with better theming and unstyled components. The first version shipped in April 2024 and reached 1.0.0 in December 2025. The momentum shifted decisively in 2026: shadcn/ui, the most widely used UI framework in React, announced support for Base UI and then made it the default, citing the community's clear preference. Radix itself still exists and is maintained by WorkOS, but the center of gravity - and the ecosystem's default choice - had moved to the fork (or rather, the re-implementation) led by the original authors.
WorkOS acquires Modulz, the company behind Radix Primitives.
Radix development slows sharply; the original creators leave for MUI.
MUI announces plans for Base UI.
The mui/base-ui repository becomes public.
Base UI reaches 1.0.0.
shadcn/ui makes Base UI its default, following community preference.
“We're building Base UI for the entire React ecosystem.”
“Base UI is the future of accessible React components.”
“From the creators of Radix, Floating UI, and Material UI.”
Base UI changed the meaning of 'fork': it contains none of Radix's code, yet it is functionally Radix's successor because the same people wrote it. Its 2026 win of the shadcn/ui default sent a signal through the entire React ecosystem about what happens to libraries whose maintainers are owned by companies with different priorities.