Earlier quoted context omitted.
There's nothing stopping a window manager from supporting docking windows to each other, or the more common option in tiling window managers of having nested tiling groups so you can arrange your editor windows however you like and manipulate them together. Metisse [1] takes it even further, letting you slice a ‘palette’ out of one window and put it in another. In practice I, like you and I suspect a lot of other peo…
There is a lot of stuff that window managers could in theory do (e.g. something i'd like Window Maker to be able to do is "combining" windows so that the title bar becomes a tab bar that contains multiple windows in the same screen space region) but in practice never end up doing for whatever reasons (i could in theory spend the time to implement such a feature in Window Maker but it is very low in my priorities for…
XMonad supports tabbed groups, by the way, as (apparently) do i3wm, Sway, and Hyprland.
> Well, in the example of image editors i mentioned, these windows are views to the underlying image documents - and being able to move and resize those views arbitrarily, together with a caption about the document they're about, is very useful.
Sure, it is. That is also exactly the set of features of a window manager :)