> Works in any browser, even offline once loaded
That, my friend, is not how offline works. You will be required to have internet access in one way or another. Offline works 100% locally no matter if you have internet or not.
You're misunderstanding how websites work. You can install it locally on your computer and run it via localhost https://github.com/GridSpace/grid-apps
There's an electron build, although why you'd use it over a native slicer is beyond me.
Umm, I’m confused about this comment… the concept of a web app that gets saved into browser cache and then can be loaded and used while offline definitely isn’t new. See Photopea etc
But you have to get the software somehow? Once you get it, it works offline. The same here I guess: once you download the source code/binaries into browser's cache (that can store things indefinitely) it's offline.