What’s new in React v17, and the road to v18

React v17.0 RC, the latest release from the React team, focuses on improving the upgrade experience without introducing new visible features, marking a shift towards more seamless transitions between versions. This version allows developers to gradually upgrade parts of their applications, making it easier to manage large projects by enabling multiple React versions to coexist within the same app. Significant changes include reimagined event delegation where handlers are now attached to the DOM container rather than the document, aligning React's behavior more closely with native browser behavior. Additionally, the removal of event pooling, consistent error handling for undefined returns, and timing improvements for the useEffect Hook cleanup function are included. The update also ensures compatibility issues are minimized by retaining deprecated methods and introduces changes that better support nesting of apps built with different React versions. While private exports have been removed to enhance stability, the React team encourages testing of this version as they prepare for more stable releases in the future.