Fair enough.

Sorry, I should have clarified a bit more — I'm writing a cross-platform desktop application that has a preact[0] frontend (+ a Go backend) using `firefox --app application.ini`.

I have been experimenting with performant lists (which is why I brought up the XUL tree — it's currently central to the interface, though not the final implementation for sure) — I'm currently only using the XUL window/menubar elements in order to populate the native macOS menubar.

I am a fullstack web dev in my day job, so my goal here is to write a fast, easily extendable UI that I can quickly iterate upon using modern html/js/css/etc.

I love gecko and used to write XUL add-ons many years ago, so I'm already familiar with JS code modules, XPCOM, XUL, the internal browser architecture etc.

Basically, I'm now using XULRunner (`firefox --app application.ini` as previously mentioned — will eventually be stubbed into a native macOS .app/OS program) as a replacement for Electron / Chromium Embedded Framework[1].

I'm basically doing the same thing as Positron[2]/qbrt[3].

[0]: https://preactjs.com/

[1]: https://en.wikipedia.org/wiki/Chromium_Embedded_Framework

[2]: https://github.com/mozilla/positron

[3]: https://github.com/mozilla/qbrt

While you're definitely correct, I enjoyed working with Komodo IDE which was (is?) built around XUL even up to a few years ago. A neat API for extending and hacking around on it, with quite nice discoverability. I'm sad to see it go, but it makes perfect sense as to why!

Probably still better than anything HTML.