A very underrated flippening:

It feels like these days when open source software devs make software with UIs *that runs locally*, a lot of the time the UI is built *as a webpage* and you access it by going to localhost:3030

As opposed to…? Fat native GUIs?

It feels like open source has slowly abandoned app categories that need the latter. Last one I can recall downloading is Inkscape. 

The localhost webpage model seems mostly for text heavy UIs. I haven’t seen rich graphic UIs in that style.

Blogger at ribbonfarm.com, running summerofprotocols.com, host of /gloom ☀️

Building a UI in the browser at this point is generally easier and in most cases superior to a UI built using a native OS framework.  Not to mention, it works on every OS without any platform specific code.

There are very few situations where I think using the OS native windowing system for UI is the right choice.

Anything that needs or benefits significantly from the UI having direct access to hardware.  The most obvious of these is the video card for rendering applications and 3D games.