> My personal opinion, unrelated to any project, is that traditional multi-window is a very fragile legacy design paradigm that doesn't make any sense

That's all well and fine, no one is forcing you to build or use software this way. But there are domains where this is the predominant UX design and it's proven to be robust for decades.

Reading between the lines a bit and from browsing some mailing list posts/gh issues, it seems like Wayland developers have a deeply held arrogance towards application developers that are surprised to find out the applications they have been developing for years are "wrong." The truth is that GUI software on Linux is already a minefield (which is why most people don't bother to support it) and making it less-like-Windows is not going to make it easier for people to port their desktop applications. I get the desire for targeting things-not-like-Windows (tiling WMs, VR, tablet/mobiles, etc)... but those aren't desktop applications.

It seems crazy to me that there's so much feedback from desktop application developers that is being ignored or dismissed.

> If these are normal windows (top-levels), it won't even know where the windows are relative to each other - it just receives (surface-relative) input when focused, none when not.

So a very basic problem in a multiwindow app is: open a new window. Move it around. Close window. Reopen window, and reposition it where the user last placed it.

Normally that requires windows knowing where they are in absolute coordinate space on the display. From what it sounds like, that's not possible in wayland?

Note: I don't think it's productive to talk in terms of Wayland or X11 abstractions or terminology, since the problem is very simple and something that's pretty trivial to do on any desktop for the last ~25 years. Regardless of how Wayland presents the data to an application we can agree: an app opens "windows", a user moves them around, and then the app may want to recreate equivalent windows at the same position later, right?

I've worked on CAD software in my career, and some other domains with "special" UI considerations and it's worth pointing out that this kind of commentary is dismissed and ignored by the developers of this software, because it doesn't line up with what real users of the software report or request.

> Not at all how things work, no. :)

It is, though. If something works as you expect on the platforms where the majority of your users are then the weird one is just going to be ignored.

> The historic reason is that all inputs and window manager state outside your very own window is kept secret, and "stealing" input strictly disallowed.

For multi-window applications you're not inside "your own window", you own many windows. Are apps not allowed to get and set properties of windows they spawn under Wayland?

I haven't worked on desktop UI in years, but that's very surprising to me if true.