Whereas the Mac has always had one-window-per-document, many Windows apps (including Office 2003, and maybe later versions) have one-window-per-app, with documents as “sub-windows” within that window. OK, I say, it’s a different paradigm – give them the benefit of the doubt.
But now I have 2 versions of a spreadsheet I need to compare. I want to put them on two monitors, but the application window zooms up to fill just one monitor, and I can’t move the document window outside of it. I could try to manually stretch the application across the two monitors, but they’re different ratios, so it’s difficult to make it fit. I tried opening two “instances” of Excel (another concept that seems unfortunate to me as a Mac user), and that almost works – I can put one app window on each monitor. But then, when I want to copy a spreadsheet tab from one to the other, the two apps are independent and don’t recognize that the other is open.
One-window-per-document would be a nice solution!