It is our pleasure to announce the availability of Quarkus 4.0.0.Beta1, the first Beta of the next major version of Quarkus.Quarkus 4 is a major new version and comes with a lot of changes.The final release is planned for the end of November.We need extension developers to migrate their extensions and end users to test their applications with it.Your feedback at this stage is essential to make Quarkus 4 a great release, please report any issues you encounter on GitHub.HighlightsQuarkus 4 comes with significant upgrades across the board, and more are coming:Java 21New base Java version, making virtual threads more central.Netty 4.2 and Vert.x 5.xNew foundation for the networking layer.QUIC supportQUIC is becoming the new foundation of distributed systems: HTTP/3, MQTT over QUIC, WebTransport (WebSocket over QUIC)…​HTTP/3Opt-in support for HTTP/3 with automatic certificate generation in dev and test modes.Native transportsImprove the concurrency of your application with epoll or io_uring support.Also works in native executables.Observation API@Observed or programmatic API to generate metrics and traces.Works with Micrometer and OpenTelemetry.Dev UI Observability dashboardBuilt-in Observability section in the Dev UI, available out of the box in dev mode with no wiring needed.Jakarta REST 4JSON Merge Patch, new multipart API.Hibernate ORM 8Integration of the new major version of Hibernate with Jakarta Persistence 4.0 and Jakarta Data 1.1.Jackson 3New major version - everything has changed except for the annotations.CDI 5.0New annotations such as @Reserve and @Eager.New JMS extensionDedicated JMS extension with compatibility with Spring JMS, pooled JMS, and IronJacamar.@ExactlyOnceImproved Kafka transaction support.Upgrading to Quarkus 4Migration guideWe wrote a migration guide.As expected for a new major version, it is more dense than for our usual minors.For extension developersIf you are maintaining a Quarkus extension, now is the time to start migrating it to Quarkus 4.The migration guide contains all the information you need.Please reach out to us on Zulip if you have any questions or need help with the migration.Come Join UsWe value your feedback a lot so please report bugs, ask for improvements…​ Let’s build something great together!If you are a Quarkus user or just curious, don’t be shy and join our welcoming community:provide feedback on GitHub;craft some code and push a PR;discuss with us on Zulip and on the mailing list;ask your questions on Stack Overflow.