- Breaking changes include moving key and ref off props to element level, making default props static at creation, removal of React.internals, requiring createFactory for composite functions, and enforcing lowercase JSX tags as HTML.
- New features add the spread operator ({...}) for props, support for additional HTML attributes, React.addons.batchedUpdates, and JSX sourcemap options while dropping the @jsx React.DOM requirement.
- Extensive deprecations (e.g., React.render*, various PropTypes) and bug fixes improve event handling, error stacks, devtools integration, and HTML attribute handling.
Community impact
Community ratings: 0 Useful, 0 Noise, 0 Risky, 0 Broke, 0 Try.