The more I see pull requests from LLMs and experiment with it myself the more convinced I am that it produces just about the worst code I've ever seen. Not just bad on style, but inefficient, often incorrect, and usually the wrong approach. It "works" in the loosest sense of the word.

I keep hearing how AI will make software so easy to write and yet Gmail still hasn't evolved beyond the mid 2010s.

I'm planning to add direct support for WASM libraries to JRuby so that you don't have to do any of the plumbing to boot up Chicory and bind the exposed functions. Imagine something like JRuby's Java integration, but you just `require 'mylib.wasm'` and call it from Ruby!

Here's a use of AI I can get behind: JRuby support for native Ruby libraries using Chicory WASM for JVM and JRuby's JVM integration! RBS (static types for Ruby) uses a C ext on CRuby, but with this PR it now works on JRuby. JRuby support could really expand with this pattern! buff.ly/SDAtXId

Our friends over at @fastruby.io have posted a nice compatibility matrix for JRuby versions, covering Ruby and Rails compatibility. Check it out to learn how the versions line up or if you haven't already discovered how JRuby can help you run Ruby and Rails better! www.fastruby.io/blog/jruby/r...

concurrent-ruby 1.3.7 is released and fixes 3 security vulnerabilities: github.com/ruby-concurr...

githubstatus.com has overtaken github.com/<anything> in my local browser as the most frequent site I visit after typing "git..."

Today's AI test: see if Copilot can fix a networking test that sometimes times out. Ran for 5 minutes, changed two InetSocketAddress constructors to use getLoopbackAddress even though the old forms called anyLocalAddress. Fail. The actual fix was to increase the timeout due to slow GHA runners.

Exciting demonstration of how fast JRuby can really be when you sweep away some of the metaprogramming layers of a typical Rails application... even when it already handles Rails HTML requests 2x faster than CRuby! Looking forward to seeing more about Roundhouse.

And it's live! I'll show you the latest and greatest use cases for using JRuby with *real world* examples at RubyConf 2026 in Las Vegas, July 14 at 3:30PM! Tell your friends! rubyconf.org/schedule/

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 9.4.15.0 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...

"I didn't do this thing because it was easy... I did it because I thought it would be easy." - Radan Skorić at RubyConf Austria 😂

In about an hour I'll do my first solo JRuby workshop at RubyConf Austria! I've used this opportunity to start assembling a complete JRuby tutorial, and I'd love to include your ideas. Check it out:

I've started a project to collaboratively build templates for JRuby on Rails! So far there's just the bare minimum Rails 8.0 template I posted about earlier this week. Rails template experts are desperately needed, as well as anyone who has an idea for JRuby on Rails templates! buff.ly/XJEOrWg

A wild idea appears... what if you could use JBang with JRuby as a complete Rails command line... no JVM or JRuby installation required? jbang rails@jruby new blog cd blog jbang rails@jruby generate scaffold ... It just needs some tweaks to work. Interested?

Exciting news! We have published 80.0.pre1 gems for JRuby's activerecord-jdbc-adapter for Rails 8.x, as well as a template you can use (thanks to Karol Bucek) to `rails new` a fresh app! buff.ly/V6AeM5H JRuby on Rails is BACK and we're excited to see what you do with it!

We're getting ready to finally release Rails 8.0 and 8.1 adapters for ActiveRecord on JRuby! I've set up the CI build to start producing prerelease gems for anyone that wants to give it a try. Hoping to have an official release in the next week or so. (Scroll to bottom): github.com/jruby/active...

Call me paranoid, but I'm starting to see signs that there's folks actively sabotaging my work on JRuby... advising conferences not to accept my talks and projects to drop JRuby support. It's really disheartening to me after dedicating so many years to the Ruby and JRuby communities. 😢

As part of fully automating JRuby releases, I'm trying to get the Install4J Windows installer to build and verify at a command line. Is there still value in a Windows installer without a Java runtime included? Installing JRuby is basically just "install Java; unzip JRuby; add to PATH".

Finally getting around to automating a bunch of manual JRuby pre-release verification tasks so they always run in CI. At this point, each commit will build a full release, unpack src and test build it, unpack bin and CRUD a simple rails app. More to come.

Looks like it would be pretty easy to write a JVM backend for Spinel.

It's crap like this that makes me not want to ever get anything at @Starbucks. I can't afford a bunch of ads in my notifications.

It's still shocking to me that after 20 years working on JRuby I won't be speaking at RubyConf. The conference that got me started on this whole crazy journey doesn't think I'm worth a talk. Really disappointing. I'll still be in Vegas to meet up, but I won't be at the event.

My pre-breakfast project: adding FreeBSD and OpenBSD to JRuby's CI. FreeBSD largely works, but some specs fail that maybe never worked on FreeBSD to begin with. The OpenBSD image I'm using doesn't have JDK 21 in ports. It's a start... feel free to assist! github.com/jruby/jruby/...

Still deep in Japan withdrawal, now back in the US. It's a real shock to the system coming home to the American suburbs after seeing the beauty and efficiency of Japanese daily life. I'll just try to incorporate as much of what I learned into my routine.

I've posted about this before, but if you're frustrated with tools like Intuit's Mint going away, the absolute best option for personal budget tracking is Monarch. They've recently added a "Plus" version for biz expenses. Referral code gets you 50% off. buff.ly/WLzGAhc

Managed to get back to Kikanbo for my double-oni ramen of the trip (demon level spice, demon level szechuan). Evil stuff. Earned my special Oni candy as a result. Definitely one of my top five restaurants in the world.

There's a disturbing trend of developers I've known for years now suddenly being unable to discuss even basic aspects of software development. They have become so dependent on LLMs, they can't even describe how to design a system anymore. Feels like losing friends to dementia. 😢

I have an idea to statically compile mruby applications to native code with hardly any dynamic dispatch. I need to make mruby for JVM, apply my secret trick, and compile to native with GraalVM. Result would be tiny and very, very fast. Need to find a sponsor.

TIL I can karaoke Meatloaf's I Would Do Anything For Love (But Won't Do That). Damn near kills me but that seems like par for the course.

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_...

So frustrating watching the Ruby community reinvent what JRuby and the JVM already do. Why don't they just use JRuby? Because we don't support the C extension API. Now they are realizing they can't do what JVM does and also support C extensions. 🤦 Seriously... just use 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! www.jruby.org/2026/04/21/j...

Ran into some friends on the way to #rubykaigi! Also, never be at the edge of a wide angle photo! 🫃

The artwork for #RubyConfAT is amazing! I'm SO excited to visit Vienna for the first time!

Lunch bags at #wroclove.rb day 2... `w` as wege (veg) vs M as in meat. 😂

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?!

Excellent, densely-packed talk by @twnsnd.com at #wroclove.rb, starting with a short history of Rails and leading to modern best practices for tight, fast, nearly JS-free (no React!) web frontends. Makes me want to build something with a spicy-hot JRuby backend!

SHOCKER! For a simple piece of code like "Array.new(10_000_000) {Object.new}", JRuby 10.1 with JDK 26 and compact object headers uses LESS REAL MEMORY than CRuby 4.0. That's just crazy. Real parallel scaling AND lower memory use?!

This year we’re going big — two conferences instead of one. That also means we need more support. Give us a hand: make a repost, tell your community, pitch to employer — anything helps, and we’ll make it worth it. Proposal: https://balticruby.org/ #ruby #conference #sponsor

Note to self: don't ask AI (ChatGPT) to generate realistic flight maps. How many errors can you spot? I'll get you started: MSP is not in Georgia.

Feels good to be on the road again! For the first time since 2007 I'm traveling all the way around the planet! Currently at Schiphol en route to Wroclaw, Poland for wroclove.rb. Saturday I fly to Japan for RubyKaigi. Then home... a full orbit! I'll be two days ahead of you! 😵‍💫

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.

At what point do I just start ignoring dependabot, and then I'm right back where I started?

Frequent conversation: > Why don't you use AI for this task? I tried. It failed to do it better than me.. > You must be doing it wrong. Great, here's the task, try it yourself! > I see the problem. These models don't do that task well. Isn't that what I just said? 🙄

My son has a low-cost ticket for #RubyKaigi available right now! Help him out and buy this ticket off of him! x.com/i/status/204...

Owning a 3D printer is saving me so much money printing parts for my 3D printer. Wait a second... 🤔

This is why AI will never defeat me.

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! www.jruby.org/2026/04/06/j...