Ruby 4.0.0

Ruby 4.0's parallel execution improvements are a game-changer for the ecosystem. The ruby::Box feature addresses one of the biggest pain points - GIL limitations - while maintaining Ruby's elegance.

What's particularly exciting is how this positions Ruby for modern workloads. With proper parallelism, Ruby apps can finally compete with Go and Node.js in concurrent scenarios without sacrificing developer happiness.

The typing improvements also can't be understated. Gradual typing strikes the right balance - it helps teams scale codebases without forcing the verbosity of Java or the complexity of TypeScript's type gymnastics.

Looking forward to seeing how the Rails ecosystem adopts these features. This could spark a Ruby renaissance in 2025.

It's never Christmas without a new ruby version.

The ruby::box thing looks pretty interesting, from a cursory glance you can run two simultaneous versions of something like a feature or rollout much more conveniently.

Also being able to do

  if condition1
     && condition2
    ...
  end

It wouldn't be Christmas without a new version of Ruby. Thanks Matz and co!

Ruby is amazing. I recently built a layer on top of Rails that can generate an API from a single markdown file. I did the same thing in python but it was much harder and JavaScript would have been a beast. Ruby can meta program like nothing else.

Glad to see internal stack traces cleaned up (maybe we can get relative paths some day?) and Set finally get the respect it deserves!

I'm happy to see v4.0, but 2025 was the year I switched from Ruby to Python after gradually drifting back to it more and more. The tipping point was when I had Claude Code automatically convert one of my Ruby projects to 100% Python - and after that, I just had no Ruby left.

I spent over a decade enjoying Ruby and even wrote a book about it. At this point, though, Python has won for me: fastapi, pytorch, langchain, streamlit, and so on and on.

It's a bit sad, but I'll always remember the Christmas gifts, and the syntax that is always so much better than Python.

Still love Ruby deeply even though I now work somewhere where it's not in use. Thanks for the release, I hope I find a reason to use it!

Have they improved tooling? I've yet to get any lsp working on windows

Exciting to see Ruby 4.0.0 released! The new conditional syntax improvements (if condition1 && condition2) are really elegant. The Ruby::Box feature for true parallelism looks particularly promising for CPU-bound workloads. This could significantly improve performance in scenarios where we've historically had to resort to external services or other languages. Looking forward to seeing real-world benchmarks and adoption patterns emerge.

What's the relevance of ractors to the average web dev? Will ractors be useful directly in controllers/models/tasks? Or is it more that ractors will be useful to those working on the ruby language (and perhaps some gems - lower level stuff, perhaps), and therefore to the average ruby(/rails) programmer things 'just work', but faster?

It seems Ractor is still work in progress while Fiber has matured a lot in the last few releases.

I vaguely remember reading Shopify is using Fiber / Rack / Async in their codebase. I am wondering if Rails will get more Fiber usage by default.

3.x has been awesome, let's hope 4 will be even better!

My best Christmas gift <3 Love you Ruby.

Ruby::Box looks useful.

It truly is Christmas.

This really makes Christmas festive. I don't think I need new features, but sure love simplicity of 4.0.

I am installing it now. Thank you Matz and team.

I haven't looked at Ruby for a long time. I've moved away due to the lack of typing. Any degree of typing would be helpful. Does it support typing yet?