Image courtesy of Wikipedia.
Microsoft Windows features non-overlapping windows, drew a bit of interest, but failed to capture the mind-share and marketshare of its popular predecessor. I am, of course, speaking of Windows 1.0 and MS-DOS. But, the description fits Windows 8 and Windows 7 too. Windows 1.0, however, could do something Windows 8 Metro (Modern Design) cannot: Windows 1.0 could display more than two tiled windows at the same time.
The designers of the update to Windows 8, codenamed Blue, appear to be drawing inspiration from Windows 1.0. The Verge reports that Blue will allow more than two tiled windows too. Unfortunately, only a single row of tiles will be allowed. I encourage the Blue design team to take a closer look at Windows 1.0 (see screenshot above) to draw from its advanced 1985 design.
Image courtesy of The Verge