Citing "sources familiar with the matter," Windows Central is reporting that Microsoft could be bringing a tabbed interface to Windows 10 apps. There have long been calls for Explorer to support tabs so that multiple locations on the file system can be browsed without a proliferation of windows, but the report says that Microsoft may be going a step further, bringing tabs to just about every window.

The feature is apparently called "Tabbed Shell;" it would allow any application with multiple windows to have those windows collapsed onto one another by creating a tab bar. Conversely, tabs can be torn off the tab bar to create separate windows, providing an appearance and experience that mirrors that of the Edge browser.

With this, Microsoft could neatly meet the demand for tabs in Explorer and similar requests to have tabs for the command-line.

The report suggests that there will be an API so that applications can customize and better integrate with the tabbed interface if they choose. Simple applications like Notepad might not use this API, but for programs such as Word and Excel, which use a custom title bar and window frame, the API would ensure that the tabs acted as if they were a "built-in" part of the program and not merely an add-on.

Windows Central's sources are uncertain on when Tabbed Shell will materialize. It is claimed to be considered for both the Redstone 3 and Redstone 4 timeframes. Redstone 3 is due in about six months, with Redstone 4 coming a further six months on.

More broadly, Microsoft is believed to be working on a large overhaul of the Windows shell and appearance. Redstone 3 and 4 are expected to introduce a refined design language that makes greater use of motion and some subtle transparency effects, and there have also been reports that the company is working on an adaptive shell, called CShell (for "Composable Shell") that should provide a more consistent Start menu and taskbar between the desktop, Continuum on mobile, Surface Hub, and even 3D.

The Tabbed Shell concept also suggests that Microsoft is continuing to invest in Windows' basic window management. For something so essential to an operating system named "Windows," for a long time Windows' window management capabilities were quite rudimentary. Windows 7's Aero Snap, which allows easy docking of tiling of windows, and Windows 10's virtual desktops were the first real improvements to window management since the days of Windows 3.0. Adding tabs will give Windows users another tool in their toolbox for arranging their workspaces.

Ironically, if Windows users had these richer tools for managing tiled, non-overlapping windows, the Windows 8 interface and its propensity for full-screen applications might not have been nearly the shock that it was.