Kino: A high-performance Ractor web server for Ruby 4.0

It will be interesting to see the Ruby Rails direction on ractor vs Fiber. Shopify is testing on Falcon / Fiber for production already.

Edit: Turns out they are working on Ractor as well

( https://railsatscale.com/2026-08-11-ractors-on-rails/)

I've such fond memories of Ruby. Just moved to Kotlin since and it feels like a Ruby-with-types-and-Java-interop. Both Ruby and Kotlin are OO-first but FP-ready. Both are very expressive.

Interesting enough the JVM is so much further ahead that my HTTP-server is implemented "in JVM" (the built in "Sun" HTTP server is good enough for production use in our case). Where as in Ruby land there was (and is) always a native HTTP-server in the dependencies of a production app.

Excited to see the recent momentum for Ractor in Rails as well as base Ruby!

https://yaroslav.io/opensource/kino

Where is the documentation?

I am sorry but this is really a problem in the ruby world. Everyone sees how much ruby is struggling right now, yet key problems, such as documentation, are not a focus. Look at rack, ruby-wasm, ruby-opal and many other projects. Too many ruby developers hate documentation. There are a few exceptions (Jeremy Evans projects typically have a strong focus on documentation, for instance), but by and large I don't understand why documentation is always an afterthought of most projects.

If you look at the github page at https://github.com/yaroslav/kino, and search for the keyword "documentation", you get zero results. I would instead have expected at the least a link with extensive documentation, both project-internally, but more importantly, via specific examples, a useful FAQ, and most importantly a kind of extensive "how to use this". Even ruby on rails, by the way, understood that this is important, and they have a tutorial (how useful that is, is another topic, but at the least rails people understand that documentation is important; see here: https://guides.rubyonrails.org/getting_started.html)

Edit:

They have on directory called doc/ here at:

https://github.com/yaroslav/kino/tree/main/doc

But have a look at this:

"Almost all content here is written by agents (Claude Code or Codex)."

When a project is too lazy to write documentation by a human, and instead resorts to AI slop spam, then why should real human use this? I don't get it. Is the ruby world nuts now? All that pointless AI slop spam? A lot of it is unreadable to me, it makes no sense. I am noticing this with Hiroshi Shibata, before he had difficulty with english, now he writes perfect english - aka AI slop. And the generated words STILL MAKE NO REAL SENSE. I read a lot of it and it is gibberish nonsense. It is like babelfish, only slightly improved. Mankind is actively getting dumber now.

High-performance and Ruby. An oxymoron. SCNR