> The ability to overlap is also actually pretty valuable for me. Often I don't need to see a whole window, just the pertinent portion, and sometimes window edges peeking out from behind my browser window act like post-it note style reminders.
I have occasionally thought about a system where you can zoom and scroll a view on a window, but without telling the program that you're doing it. So for example, you could crop into say firefox and only show the actual page (completely cutting out toolbars and such) without it resizing itself. This is mostly of interest on smaller screens, but it'd still give you efficiency gains on a bigger screen.
Firefox has two forms of zooming, one of which resemble what you're describing.
1. Zooming with Ctrl++ or Ctrl+- will "tell the page" that it's being zoomed and it will reflow into the new viewport size.
2. Zooming with two-finger pinch (requires a touchpad) will zoom in as if magnifying the page. Content on the page will overflow to the right instead of reflowing.
Supporting an equivalent on regular desktop windows could be pretty useful.
That would be a useful feature, so long as there's some associated UI that makes it obvious that the feature is active along with an easy way to toggle it off. Seems like it could be one of those features that users accidentally trigger without realizing it and then feel "trapped" not knowing how to make it stop.
I have occasionally thought about a system where you can zoom and scroll a view on a window, but without telling the program that you're doing it. So for example, you could crop into say firefox and only show the actual page (completely cutting out toolbars and such) without it resizing itself. This is mostly of interest on smaller screens, but it'd still give you efficiency gains on a bigger screen.