I test Boxer, Notepad & Notepad++ for this.
Boxer yields the same result as SE. That is the tiled windows have the standard document layout.
Notepad++ does not allow tiled windows at all. So, you cannot even create the unusual editing layout that you provided. In Notepad++ you must use tabbed windows. If the option is there, I missed it.
Notepad only allows one document per window.
-- See attached screen shots.
The tone is which you presented the problem led me to think that SE may have been some sort of "outlier" in this regard but it is not. This seems like a contrived problem. That is, the layout you provided would not be useful for most (nearly all?) programmers. Yes, you may like it but if this were a common request it likely would be built into SE already. That said, border-less tiled windows might be a neat new feature request but I am certainly not surprised that it does not currently exist; Especially after testing other editors and considering the number of users that would prefer such a layout.
>> stop fixing problems which I don't have
I don't think this is fixing or not fixing anything. It is a typical MDI behavior. Could that be customized\overridden? Probably with programming effort.
All of your posts have quite an angry\aggressive\condescending tone to them. I really don't understand it?.?
I noticed that your attachment is named "stupideditor.png". The editor doesn't look stupid...
Sincerely, I do hope your week gets better.
Best, Jim
Note: This post in in the User Macro section of the forum. As it is not about macros, my guess is that it was posted here by mistake. You may want to re-post in the main SE forum.