Show HN: A Tiling Window Manager for Windows, Written in Janet
166 agentkilo 50 5/20/2025, 3:08:42 PM agent-kilo.github.io ↗
Hi HN!
I read[1] about Janet[2] some time ago, then immediately got impressed by the enthusiasm of its community, and by the language itself, so I started playing with it.
At the time I was searching for a tiling window manager for Windows, and unavoidably the idea of scratching my own itch with Janet got hold of me, so Jwno was born.
Simply put, Jwno is a keyboard-driven tiling window manager for Windows, scriptable with Janet. But since it has a complete Lisp runtime, and a thin wrapper library for Win32 APIs[3], you can certainly do much more with it.
I hope you'll enjoy playing with it as much as I enjoyed building it.
And yes, I use StumpWM on the Linux side, by the way.
(Browsers, in particular, I use full-screen less and less. That annoying trend of squeezing everything into short lines "because readability" is just wasting too much screen space; zooming in makes everything too big, and I'm getting tired of writing userstyles or userscript to fix it for every other page I open, so I'm back to keeping 2 or 3 columns of windows running.)
Also, any excuse to use more Lisp is good in my book. Based on the screenshots, it looks stellar; if it works half as well as it comes across, I'll switch over instantly.
I start explaining, very carefully, like I'm talking to a child, that this is an alternative shell, which replaces the standard Windows Explorer et cetera, und so weiter... it's very complicated you know...
Guy says, "cool... hey, why don't you check out this URL?". I do. It's the litestep contributor page. His nick is on it. Near the top.
Ow.
[1] https://bb4win.sourceforge.net/bblean/
[1] https://90s.dev/technical/architecture.html#shells
Brings back memories !
I've recently started playing around with Janet, and it's a great language. I think it's inspired by Clojure and Lua, and somehow manages to be better than both (in my opinion).
This is exactly how I feel about Janet too. I don't think I have enough experience on Clojure or Lua to comment on them, but I got attracted to Janet almost immediately.
Working on Jwno also confirms my first impression on Janet: It's really a practical language. The tooling has some room for improvement, but the language itself can get things done - usually fast and easily.
[0] https://GitHub.com/CFiggers/janet-lsp
I think Racket and Scheme don't belong in there because neither has a REPL as powerful and "interactive" as Common Lisp REPL. They don't support images either (but Janet and CL do).
I tried various lisp dialects, but I could never find the killer feature vs other languages I already use. And I can justify why I use these specific languages I do use, if that makes sense.
I think Jwno's REPL module is so important, I specifically changed Jwno's architecture at one point to make it work.
Sure, but any particular reason you picked Janet over Common Lisp? They both support images, REPL, hot-code-reloading, etc.
You're kidding or trolling? Structural editing and the REPL are the greatest features of Lisp. The ability to just grab any expression and move it around simplifies so many things when coding and refactoring. With the connected REPL you can eval anything on the spot, that turns the entire experience of coding into a video game — you don't need to wait for linter, linker, compiler — you just run things. You often don't even have to save anything. I suspect when you "tried various lisp dialects" maybe you didn't use structural editing and the connected REPL?
Often people confuse Lisp REPL with REPLs in other programming languages, e.g. Python, where usually you have to copy-n-paste chunks of code into it. Lisp's REPLs are different in the sense that every step in Read-Eval-Print-Loop is different — in Lisp, you typically eval things right where you type them, by sending whole expressions to the connected REPL, which could be remote. We (for example) run ours in a Kubernetes cluster, that allows us to experiment with pods, running queries against the "real" DB tables, testing services "live".
Great job. Looks really interesting and useful. And a fun excuse to write Lisp.
I really appreciate it when APIs give you high-level functionality but keep the door open to lower-level APIs when you really need them.
Ironically, 90% of use I get from them is remapping Caps Lock to CTRL. Which I historically did with AutoHotkey, which was much lighter, but then there's the 10% of the time I need something else from PowerToys...
And yet, I find Windows window management far more advanced than macOS. It's ridiculous that up until recently, macOS didn't even have basic max-size functionality w/o reaching for 3rd party apps.
The one thing I’ve noticed is that it seems like Janet had a burst of interest 2020-2022 but it has since slowed down. Would love to see it become popular again. The main reason I’m using it is because I like how it’s both powerful and lightweight. I’d use clojure but I don’t want Java. I’m tempted to also try Common Lisp but so far Janet has been great.
[0]: https://github.com/joy-framework/joy
Maybe the most "opinionated" things in Janet are the ev stuff and fibers. I think they're done right though, you just need to be careful with the event loop when embedding Janet.
* By default, Komorebi uses dynamic tiling, while Jwno uses manual tiling.
* Komorebi has workspaces, Jwno works with Windows native virtual desktops instead.
* Komorebi uses IPC and native system command line to send commands, while Jwno usually operates all by itself.
There are definitely other details that are important to you, but these are the things that immediately came to my mind. I don't run Hyprland so can't really comment on that.
https://github.com/LGUG2Z/komorebi
The Windows tiling window manager development scene is a very kind, relaxed and collaborative space where we all take inspiration from and support each other
The Linux scene isn't bad either (or at least it wasn't 4+ years ago when I was into this); I've used StumpWM as a daily driver for many years, and while it was definitely niche, I still saw friendly exchange of ideas and experiences with people using and/or contributing to dwm, i3, and ratpoison.
(Then there's EXWM, but I never really mustered the courage necessary to try it.)