JRuby Dev Team

Operated by @headius, @tom_enebo, @hiro_asari

[JRuby Dev Team @jruby]

We're happy to announce jruby-rack 2.0.0, updating our servlet/rack bridge to support the Jakarta Servlet API! We partnered with JRuby contributor https://t.co/dAZJ5rAsMH and the @killbill_io Open Source billing and payments platform to make this happen.
https://t.co/DTdbh4aP7F

[JRuby Dev Team @jruby]

JRuby 10.1.2.0 is released! JRuby 10.1 is our edge line, with more aggressive performance work and refactorings. This release improves perf of Ruby classes that extend Java, startup time on MacOS, and includes many stdlib updates.
https://t.co/aYhK9gsDfy

[JRuby Dev Team @jruby]

JRuby 10.0.7.0 is released! JRuby 10.0 is our stable line, receiving only bug and security fixes and critical performance improvements. This release tidies up another round of compatibility issues and updates a few standard libraries.

https://t.co/iCdNqYgrZo

[JRuby Dev Team @jruby]

Hello JRubyists! Anyone planning to be at tiny ruby #{conf} 2026 in Helsinki next week? We'd love to help you spread the word about JRuby to the Helsinki Ruby community! Get in touch if we can help you in any way!

[JRuby Dev Team @jruby]

JRuby 10.1.1.0 is released, with a bunch of compat fixes, more performance work, and several third-party CVEs resolved. JRuby 10.1 is our active development branch, with 10.0 being stable. Upgrading is recommended if you want the latest and greatest!
https://t.co/fEpJYVinGq

[JRuby Dev Team @jruby]

Our friends over at @fastrubyio have posted a nice compatibility matrix for JRuby versions, covering Ruby and Rails versions.

Check it out to see how the versions line up or to learn how JRuby can help you run Ruby and Rails better!

https://t.co/fdD4nv80ZZ

[JRuby Dev Team @jruby]

JRuby 10.0.6.0 released! Updated jruby-openssl, faster Java interface support, and many other fixes and improvements. JRuby 10.0.x is our LTS version, so upgrading is recommended.

https://t.co/PCg21ODjmX

[JRuby Dev Team @jruby]

JRuby 9.4.15.0 is released! This is the last regularly-scheduled release of JRuby 9.4.x and includes the last set of 9.4 fixes. Future releases will be done as needed for commercial JRuby users. Contact us if you need long-term JRuby 9.4 support.

https://t.co/4kPdka64Gx

[JRuby Dev Team @jruby]

JRuby 10.1 is released! We've caught up with CRuby 4.0 after less than four months, and pushed a bunch of new optimizations: smaller objects, smaller numerics, and groundwork for many more. We'll maintain 10.0 as our stable line, but do try 10.1 yourself!
https://t.co/m5xI9AMgq2

[JRuby Dev Team @jruby]

JRuby 10.0.5.0 is released! This round we fixed some memory leaks when embedding multiple JRuby instances, a few pesky Windows bugs, and several Ruby compatibility blockers. Enjoy!
https://t.co/5ARuxLXADb

[JRuby Dev Team @jruby]

Today we were informed of a low-severity vulnerability in the bcrypt-ruby gem. We worked with the maintainers to arrange a fix. Upgrading is recommended.

CVE-2026-33306: Integer Overflow Causes Zero Key-Strengthening Iterations at Cost=31 on JRuby

https://t.co/Ob6JAGYQ3k

[JRuby Dev Team @jruby]

JRuby 10.0.4.0 is released! A month after 10.0.3.0, we've addressed lots of one-off issues, a few memory and thread-safety fixes, and general compatibility and stabilization work. Enjoy!
https://t.co/GIJiiR8WZk

[JRuby Dev Team @jruby]

JRuby 10.0.3.0 is released! Over 80 issues and pull requests and 13 external contributors combined to help further stabilize our 10.0 series! There's lots of compatibility fixes, a few performance enhancements, and a number of library updates.

https://t.co/teZlO0KahQ

[Charles Oliver Nutter @headius]

New post: Warbled Sidekiq: Zero-install Executable for JVM

Previously, I showed how to use Warbler to package a simple tool as an executable jar. This post will demonstrate how to “warble” a larger project: the Sidekiq background job server!

https://t.co/6Bv0Ndly1F

[Charles Oliver Nutter @headius]

New post: "Packaging Ruby Apps with Warbler: Executable JAR Files"

Warbler is the JRuby ecosystem’s tool for packaging up Ruby apps with all dependencies in a single deployable file. Let’s use Warbler to create all-in-one packaged Ruby apps!

https://t.co/uNyZ7Iu6Lh

[JRuby Dev Team @jruby]

Warbler 2.1.0 has been released! Warbler allows you to package JRuby applications (with obfuscation of code) as a single binary, either a .jar file you can run directly or a .war file you can deploy to any Java application server. Blog post coming!

https://t.co/ZpUtxYKrFp

[JRuby Dev Team @jruby]

We have published Docker images for JRuby 9.4 and JRuby 10 on JDK 25! The -dev images are also updated to latest commits. Give them a try and let us know if there's any issues!

[Charles Oliver Nutter @headius]

At the end of my post on JRuby and JDK 25 startup time features, I teased a bit of the unreleased improvements from Project Leyden. It turns out the latest commits improve startup time even more, so it seems worth posting a quick follow-up!

https://t.co/OJavH9BpXQ

[Charles Oliver Nutter @headius]

New post: JRuby and JDK 25: Startup Time with AOTCache

Let's take a look at JRuby's startup time journey, all the way up to using JDK 25's AOTCache and Project Leyden features coming to a JDK near you soon.

https://t.co/aw4G6MKoo5

[JRuby Dev Team @jruby]

JRuby 9.4.14.0 is released! We've updated a bunch of the standard library (including "cgi" to fix a couple of CVEs), fixed a few memory leaks and a bunch of compatibility issues, and generally stabilized things. Upgrading is recommended!

https://t.co/X4FoGd4q33