We have released jruby-maven-plugins 3.0.6, updating JRuby to 9.4.13.0 along with several other improvements. But more exciting: Warbler is BACK! We've updated it for latest JRuby and dependencies and it's running green in CI. Time for feature requests!.

FYI: now that Ubuntu 20.04 is EOL, future releases of the JRuby Docker image will be based on Ubuntu 22.04. This will take effect with releases 9.4.14.0 and 10.0.1.0, whenever they happen. See

JRuby 9.4.13.0 is released! We have fixed several user issues, including a slow leak in Java interface implementation, a possible deadlock between JIT and main threads, and backported launcher improvements from JRuby 10!.

RT @nanovms: this week on the unikernel application spotlight we check out @jruby real threads && jvm interop - con….

RT @headius: That's right. JRuby is the only Ruby with a fully-portable, all-in-one distribution that works with Bazel's secure, closed-w….

RT @wnyconservative: One of my benchmarks for learning German is being able to construct Alle Kinder jokes, about whatever topic I happen t….

Security advisory: We have released jruby-openssl gem 0.15.4, jruby 10.0.0.1, and jruby 9.4.12.1 to address CVE-2025-46551, disabled hostname verification by default. We recommend that all users upgrade!.

RT @headius: Seems like a few folks didn't think my 2D bar chart was "beautiful", so let's kick it up a notch with 3D, SVG, and PDF generat….

It's finally here! JRuby 10 has been released with support for Ruby 3.4 (including 3.2 and 3.3 updates as well). Minimum Java version has been bumped up to Java 21, allowing us to support more modern JVM features. Begin your migration today!.

RT @headius: It's almost time! I've just published my first post on JRuby 10, "Part 1: What's New". More posts will follow in the coming we….

RT @headius: We have released jruby-launcher 2.0! This version eliminates the old C++ code in favor of two options:. * On Unix systems, jus….

JRuby 10 HEAD builds are now live in GitHub Actions setup-ruby and for any local Ruby installers that depend on jruby-dev-builder's jruby-head packages! Fingers crossed it doesn't cause too many problems, but let us know right away if something goes awry!.

It's almost time! JRuby 10 is approaching release, and toward that end we will be switching JRuby master from the 9.4 line to the 10.0 line this week. The "jruby-head" build from GHA "setup-ruby" action will remain 9.4 for now, but it's time to start testing with JRuby 10!.

RT @headius: New post: Boosting JRuby Startup with AppCDS and AOT caching

JRuby 9.4.12.0 has been released with two important fixes: a thread-safety patch for recent Class#subclasses logic and an update for jar-dependencies to fix issues parsing Maven output on Java 9+. Let us know if you run into any new issues!.

JRuby 9.4.11.0 is released with two critical fixes for bugs in 9.4.10.0 and a handful of stdlib upgrades. We recommend all users update to 9.4.11.0 and skip the 9.4.10.0 release. Let us know if you have issues!.

We have released jar-dependencies 0.5.2, now that JRuby 9.4.10.0 can safely handle upgrading it independent of JRuby itself. This finally fixes issues sourcing jar dependencies from Maven in containerized environments (previously partially fixed by updating ruby-maven-libs).

JRuby 9.4.10.0 is released with over 50 issues and PRs! We've included some key targeted optimizations along with many user-facing bug fixes, library upgrades, and usability improvements. Upgrade today!.

RT @headius: Psych 5.2.3 has been released. For JRuby users, this updates SnakeYAML-Engine to 2.9 and fixes an issue with numeric YAML alia….

We recently released an for the jar-dependencies gem, used to fetch jar dependencies from Maven Central. Unfortunately due to a bug (fixed in JRuby 9.4.10.0) we are considering pulling it temporarily. If anyone's got jar-dependencies 0.5.0 in their Gemfile.lock, we need to know!.