React 18 has been released with new features that bring significant improvements to the React ecosystem. The New Root API replaces the Legacy Root API, allowing developers to upgrade their client without major code changes. This change also enables improved performance and responsiveness in applications. Suspense, a long-awaited feature, now offers full support for delayed transitions, placeholder throttling, and coordinated component rendering. Additionally, React 18 introduces several opt-in features, including startTransition, useDeferredValue, SuspenseList, and server-side rendering with selective hydration, which can be used flexibly throughout the application. These new features are available through the `@alpha` tag in npm, allowing developers to install React 18 and begin exploring its capabilities.