React 19.3 (September 9) makes two APIs stable: <ViewTransition>, which animates elements entering, leaving, updating or moving using the browser's View Transition API, and refs on <Fragment>, which give you DOM methods over a group of sibling elements without a wrapper div. New in React DOM: use(browser()) opts a component out of server rendering (handy for localStorage or timezone code), plus Trusted Types support. Server Components can now render a Context from a 'use client' module directly.