Ah another Electron shell being sold as "desktop".
They're common enough now that maybe we should just consider html, css, and js to be GUI scripting and markup languages in this context? Your browser is a desktop app and yet almost everything you do with it can only be done online. Perhaps it's fair to call this a Desktop app as it can be run offline, but not fair to call it a "native" desktop app.
Small collection of Electron predecessors:
https://en.wikipedia.org/wiki/Active_Desktop
https://en.wikipedia.org/wiki/HTML_Application
https://en.wikipedia.org/wiki/XUL
https://www.allaboutsymbian.com/features/item/The_Wonderful_...
Eventually Electron will join them.
XUL was replaced by HTML and CSS - the UI for modern Firefox used to be XUL, now it's HTML (actually XHTML, I guess they couldn't quite kick the XML part of it): https://github.com/mozilla/gecko-dev/blob/master/browser/bas...
Some abandoned modern alternatives included Chromeless[1], Positron[2][3] and qbrt[4][5].
While technically possible using Firefox's XULRunner functionality (`firefox --app app.ini` — mostly undocumented, potentially unsupported in the future), as far as I can tell, Mozilla has abandoned the Electron approach for XUL/Gecko bundling, which is a shame since Firefox itself is basically just an implementation on top of the Gecko XUL runtime.
> "[Firefox] is distributed as the combination of a Gecko XUL runtime — libxul, other shared libraries, and non-browser-specific resources like those in toolkit/ — plus a Firefox XUL application — mostly just the files in Contents/Resources/browser/, plus the 'firefox' stub executable that loads Gecko and points it at a XUL application" [6]
On Android, there is also Geckoview[7][8] for embedding gecko.
[0]: https://en.wikipedia.org/wiki/XULRunner
[1]: https://github.com/mozilla/chromeless
[2]: https://github.com/mozilla/positron
[3]: http://web.archive.org/web/20210227132731/https://mykzilla.o...
[4]: https://github.com/mozilla/qbrt
[5]: http://web.archive.org/web/20210601133844/https://mykzilla.o...
[6]: http://web.archive.org/web/20210227132731/https://mykzilla.o...