Very interesting day of discussions at #railsworld! Introduced a few folks to JRuby, talked with some current users I did not know, even found one shop that only does JRuby. A bit sad to see folks struggling with problems JRuby solves. Hard to get the word out!
September 24, 2026 at 4:35 AM
Very interesting day of discussions at #railsworld! Introduced a few folks to JRuby, talked with some current users I did not know, even found one shop that only does JRuby. A bit sad to see folks struggling with problems JRuby solves. Hard to get the word out!
Top three questions I got at #railsworld:
Q: Does Rails work on JRuby?
A: Yes, for 20 years now.
Q: Didn't JRuby already solve this?
A: Yes.
Q: Why aren't you speaking here?
A: I tried. Ask the organizers.
Q: Does Rails work on JRuby?
A: Yes, for 20 years now.
Q: Didn't JRuby already solve this?
A: Yes.
Q: Why aren't you speaking here?
A: I tried. Ask the organizers.
September 24, 2026 at 11:12 PM
Top three questions I got at #railsworld:
Q: Does Rails work on JRuby?
A: Yes, for 20 years now.
Q: Didn't JRuby already solve this?
A: Yes.
Q: Why aren't you speaking here?
A: I tried. Ask the organizers.
Q: Does Rails work on JRuby?
A: Yes, for 20 years now.
Q: Didn't JRuby already solve this?
A: Yes.
Q: Why aren't you speaking here?
A: I tried. Ask the organizers.
JRuby is on Bluesky! Follow for release announcements, security notifications, and general JRuby fun!
December 20, 2024 at 8:46 PM
JRuby is on Bluesky! Follow for release announcements, security notifications, and general JRuby fun!
jruby is short for jean ruby
January 14, 2025 at 3:31 AM
jruby is short for jean ruby
Calling all Rubyists! We are looking for help verifying third-party libraries on JRuby 10! I've opened an issue to track that process, and provided links to snapshot JRuby builds you can use to verify your own code. Please help us verify JRuby 10!
Check third-party libraries against JRuby 10 · Issue #8675 · jruby/jruby
We are about to switch master and jruby-head to JRuby 10, but want to try to make sure that third-party libraries testing against jruby-head do not suddenly fail. To that end, we would like to repr...
buff.ly
March 4, 2025 at 9:05 PM
Calling all Rubyists! We are looking for help verifying third-party libraries on JRuby 10! I've opened an issue to track that process, and provided links to snapshot JRuby builds you can use to verify your own code. Please help us verify JRuby 10!
Good news! I have been added to the RubyConf 2026 schedule to present JRuby and all the ways it lets you use Ruby when CRuby doesn't fit! I'm glad that the new @rubycentral.org values community and understands the importance of JRuby. Twenty years of JRuby...don't miss this talk!
June 10, 2026 at 5:53 PM
Good news! I have been added to the RubyConf 2026 schedule to present JRuby and all the ways it lets you use Ruby when CRuby doesn't fit! I'm glad that the new @rubycentral.org values community and understands the importance of JRuby. Twenty years of JRuby...don't miss this talk!
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!
JRuby 9.4.10.0 Released — JRuby.org
The JRuby community is pleased to announce the release of JRuby 9.4.10.0.
buff.ly
January 21, 2025 at 6:13 PM
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!
Big announcements coming from JRuby next week... we are ready to unleash JRuby 10.1 with a ton of improvements and some really exciting new technology. Stay tuned.
April 14, 2026 at 7:53 PM
Big announcements coming from JRuby next week... we are ready to unleash JRuby 10.1 with a ton of improvements and some really exciting new technology. Stay tuned.
My JRuby talk at #BalticRuby went great! Lots of discussions afterwards, including one shop desperate to solve some Ruby scaling issues. I'm so glad I was able to be here and looking forward to a bunch of new JRuby users! Thanks to JRuby supporter eazyBI for sponsoring me!
June 13, 2025 at 10:22 AM
My JRuby talk at #BalticRuby went great! Lots of discussions afterwards, including one shop desperate to solve some Ruby scaling issues. I'm so glad I was able to be here and looking forward to a bunch of new JRuby users! Thanks to JRuby supporter eazyBI for sponsoring me!
JRuby 10.0.2.0 will be fully green on sinatra/mustermann for the first time! (Only minor fixes required in the end.)
github.com/sinatra/must...
github.com/sinatra/must...
Enable jruby-head in CI and fix remaining failures by headius · Pull Request #145 · sinatra/mustermann
In jruby/jruby#8922 a bug was reported in JRuby 10.0.1.0 that might have been caught before release had mustermann's CI been running jruby-head builds without enabling allow-failure. This PR wi...
github.com
August 3, 2025 at 6:34 PM
JRuby 10.0.2.0 will be fully green on sinatra/mustermann for the first time! (Only minor fixes required in the end.)
github.com/sinatra/must...
github.com/sinatra/must...
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.
www.jruby.org/2026/09/21/j...
www.jruby.org/2026/09/21/j...
JRuby 10.1.2.0 Released — JRuby.org
The JRuby community is pleased to announce the release of JRuby 10.1.2.0.
www.jruby.org
September 22, 2026 at 12:05 AM
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.
www.jruby.org/2026/09/21/j...
www.jruby.org/2026/09/21/j...
Following Charles Nutter's inspiring talk about JRuby @jrubyproject.bsky.social at @wrocloverb.com, I'm happy to announce that Strong Service is now tested against JRuby 10.1.
github.com/shkm/strong_...
github.com/shkm/strong_...
Test against jruby by shkm · Pull Request #5 · shkm/strong_service
github.com
April 22, 2026 at 3:48 PM
Following Charles Nutter's inspiring talk about JRuby @jrubyproject.bsky.social at @wrocloverb.com, I'm happy to announce that Strong Service is now tested against JRuby 10.1.
github.com/shkm/strong_...
github.com/shkm/strong_...
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 modern JVM features. Check out the release notes and start migrating today!
www.jruby.org/2025/04/14/j...
www.jruby.org/2025/04/14/j...
JRuby 10.0.0.0 Released — JRuby.org
The JRuby community is pleased to announce the release of JRuby 10.0.0.0.
www.jruby.org
April 14, 2025 at 10:00 PM
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 modern JVM features. Check out the release notes and start migrating today!
www.jruby.org/2025/04/14/j...
www.jruby.org/2025/04/14/j...
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!
www.jruby.org/2026/04/21/j...
www.jruby.org/2026/04/21/j...
JRuby 10.1.0.0 Released — JRuby.org
The JRuby community is pleased to announce the release of JRuby 10.1.0.0.
www.jruby.org
April 21, 2026 at 2:28 PM
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!
www.jruby.org/2026/04/21/j...
www.jruby.org/2026/04/21/j...
JDK 25 AOT gains are already looking awesome!
Best JRuby startup times for "Hello, world":
* JDK 21 with AppCDS: 0.794s
* JDK 25 with AOTCache: 0.688s 🤯
JRuby on JDK 25 will be so much fun!
Best JRuby startup times for "Hello, world":
* JDK 21 with AppCDS: 0.794s
* JDK 25 with AOTCache: 0.688s 🤯
JRuby on JDK 25 will be so much fun!
September 18, 2025 at 3:54 AM
JDK 25 AOT gains are already looking awesome!
Best JRuby startup times for "Hello, world":
* JDK 21 with AppCDS: 0.794s
* JDK 25 with AOTCache: 0.688s 🤯
JRuby on JDK 25 will be so much fun!
Best JRuby startup times for "Hello, world":
* JDK 21 with AppCDS: 0.794s
* JDK 25 with AOTCache: 0.688s 🤯
JRuby on JDK 25 will be so much fun!
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 weeks, but JRuby 10 itself should be generally available before my RubyKaigi talk next week!
JRuby 10, Part 1: What's New
I am very excited to introduce you to JRuby 10, our biggest leap forward since “JRuby 9000” was released almost a decade ago.
buff.ly
April 9, 2025 at 3:52 PM
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 weeks, but JRuby 10 itself should be generally available before my RubyKaigi talk next week!
I have uploaded my slides from "Optimizing JRuby 10" presented at #RubyKaigi2025: speakerdeck.com/headius/opti...
Optimizing JRuby 10
JRuby 10 is out now with Ruby 3.4 and Rails 8 compatibility! After years of catching up on features, we've finally been able to spend time on long-delay…
speakerdeck.com
April 20, 2025 at 5:08 AM
I have uploaded my slides from "Optimizing JRuby 10" presented at #RubyKaigi2025: speakerdeck.com/headius/opti...
Matz is at #BalticRuby and so am I! Come learn how JRuby brings you next-gen Ruby performance, scaling, and opportunities at my talk tomorrow!#rubyfriends #jruby
June 12, 2025 at 7:10 AM
Matz is at #BalticRuby and so am I! Come learn how JRuby brings you next-gen Ruby performance, scaling, and opportunities at my talk tomorrow!#rubyfriends #jruby
It's incredible the amount of hacking required to get Rails to run in parallel with Ractors (and it still isn't there yet) when JRuby has been running Rails in parallel for decades. #railsworld
September 23, 2026 at 4:54 PM
It's incredible the amount of hacking required to get Rails to run in parallel with Ractors (and it still isn't there yet) when JRuby has been running Rails in parallel for decades. #railsworld
Hello #railsworld! I'm here at the event running office hours and teaching people how to run Rails on JRuby. Find me in the vendor pavilion and grab a sticker!
September 23, 2026 at 5:31 PM
Hello #railsworld! I'm here at the event running office hours and teaching people how to run Rails on JRuby. Find me in the vendor pavilion and grab a sticker!
Twenty years working on JRuby and delivering hundreds of talks and here's the top five questions I still get:
What is JRuby?
Why should I use it?
Do I need to know Java?
Does it run Rails?
And after my presentation:
Why isn't everyone using this?!
What is JRuby?
Why should I use it?
Do I need to know Java?
Does it run Rails?
And after my presentation:
Why isn't everyone using this?!
April 18, 2026 at 6:01 AM
Twenty years working on JRuby and delivering hundreds of talks and here's the top five questions I still get:
What is JRuby?
Why should I use it?
Do I need to know Java?
Does it run Rails?
And after my presentation:
Why isn't everyone using this?!
What is JRuby?
Why should I use it?
Do I need to know Java?
Does it run Rails?
And after my presentation:
Why isn't everyone using this?!
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!
www.jruby.org/2025/06/10/j...
www.jruby.org/2025/06/10/j...
JRuby 9.4.13.0 Released — JRuby.org
The JRuby community is pleased to announce the release of JRuby 9.4.13.0.
www.jruby.org
June 10, 2025 at 6:48 PM
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!
www.jruby.org/2025/06/10/j...
www.jruby.org/2025/06/10/j...
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 unreleased 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.
www.jruby.org/2026/06/08/j...
www.jruby.org/2026/06/08/j...
JRuby 9.4.15.0 Released — JRuby.org
The JRuby community is pleased to announce the release of JRuby 9.4.15.0.
www.jruby.org
June 8, 2026 at 6:40 PM
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 unreleased 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.
www.jruby.org/2026/06/08/j...
www.jruby.org/2026/06/08/j...
Introducing sqlite3-ffi - a drop-in replacement for the sqlite3 gem for JRuby 🎉 Passes 99% of the sqlite3 test suite and works with Active Record without a custom adapter github.com/ankane/sqlit...
GitHub - ankane/sqlite3-ffi: A drop-in replacement for sqlite3 for JRuby
A drop-in replacement for sqlite3 for JRuby. Contribute to ankane/sqlite3-ffi development by creating an account on GitHub.
github.com
April 26, 2025 at 6:33 PM
Introducing sqlite3-ffi - a drop-in replacement for the sqlite3 gem for JRuby 🎉 Passes 99% of the sqlite3 test suite and works with Active Record without a custom adapter github.com/ankane/sqlit...
Slides from my Euruko 2026 talk "JRuby: Past, Present, and Future" are now uploaded. I believe the talks were also recorded, so hopefully video will follow soon. Great event, I hope to return for 2027 in Modena, Italy!
buff.ly/paSd5t9
buff.ly/paSd5t9
JRuby: Past, Present, and Future
JRuby on Rails is 20 years old! This talk reviews the last 20 years of JRuby development, with a focus on the challenges of supporting Ruby and Rails ye…
buff.ly
September 18, 2026 at 5:03 PM
Slides from my Euruko 2026 talk "JRuby: Past, Present, and Future" are now uploaded. I believe the talks were also recorded, so hopefully video will follow soon. Great event, I hope to return for 2027 in Modena, Italy!
buff.ly/paSd5t9
buff.ly/paSd5t9