JDK 23 Release Notes

These release notes detail significant changes and new features in JDK 23, including preview language features (pattern matching enhancements, module imports, flexible constructor bodies, and implicitly declared classes), preview and incubator APIs (class-file API, stream gatherers, structured concurrency, scoped values, and vector API), performance improvements (Graal JIT integration and ZGC generational mode), tooling enhancements (Markdown documentation comments), deprecations and removals of APIs and features, notable bug fixes, known issues, and differences between Oracle JDK and OpenJDK. The notes also provide information on compatibility and migration. Annexes referencing the complete Java SE 23 API specification and its changes from Java SE 22 are cited. Finally, updated IANA time zone data is included in this JDK release.