- Add new APIs: React.memo, React.lazy, getDerivedStateFromError, contextType and server‑side support for memo and contextType; plus StrictMode warnings for legacy context API, findDOMNode, and improper <Context> usage.
- Rename unstable APIs: AsyncMode → ConcurrentMode and Placeholder → Suspense; Scheduler package renamed and now supports priority levels, continuations, earlier RAF, and improved fallback mechanisms.
- Various bug fixes: iOS Safari gray overlay, window.event overwrite in dev, enhanced DOM detection, interaction tracing bugs, and Scheduler interaction tracing improvements.
Community impact
Community ratings: 0 Useful, 0 Noise, 0 Risky, 0 Broke, 0 Try.