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A tablet displays a screenshot of the Cortana OS Start menu.

2019

Cortana OS

A gestural, assistant-first alternative to what Windows Lite could be.

Not affiliated with Microsoft

Cortana OS isn't affiliated with Microsoft. Concepts and mockups shown do not represent any product plans past, present, or future.

Microsoft is reportedly working on a lightweight OS with early reports of a "Windows Lite" product surfacing. The signals so far suggest it'll ship as some flavor of Windows. This concept proposes an alternative.

I'm calling it Cortana OS. A working title, but a deliberate one: a lightweight, gestural, assistant-first OS across modern form factors. The name matters more than it first appears, so let me start there.

Why not call it Windows

Windows RT and Windows 10 S both struggled in market for the same reason. Users brought Windows expectations to them: that the apps they already owned would work, that the OS could be used as a desktop the way every prior Windows release could. But these products couldn't deliver on those expectations. The Windows brand has become a promise of legacy compatibility, and a lightweight OS can't keep that promise without becoming the thing it's trying not to be.

Naming the product something other than Windows breaks the expectation cleanly. Users approach it with a new lens, not a worse version of something they already know.

A visual language built around the assistant

Cortana is the brand at the center of this product, not chrome layered on top of it. The OS embodies it: lighter and friendlier, with a softer geometry that reads as approachable rather than authoritative.

Mail and Store on Cortana OS — rounded corners complement the radiused corners of the display.
Mail and Store on Cortana OS — rounded corners complement the radiused corners of the display.

The most visible expression is adaptive corner radius. Cortana OS devices can ship with different screen shapes — some square, some with rounded display corners — and the system geometry responds. On a square screen, interface elements take a subtle radius; on a rounded screen, the radius pronounces to match the hardware. The OS feels like an integral piece of the device rather than merely layered on top.

The same softness runs through the rest of the visual language where type, iconography, and motion all bend toward approachability.

Gestures replace the taskbar

The simpler the surface, the less chrome belongs on it. Cortana OS has no taskbar of any kind, which raises an immediate question: how does the user navigate between apps and system surfaces?

The keyboard uses the same SwiftKey intelligence as Windows 10. System surfaces are reached by edge gestures.
The keyboard uses the same SwiftKey intelligence as Windows 10. System surfaces are reached by edge gestures.

By gesture. Borrowing the interaction vocabulary WebOS pioneered years ago and iPhone X carried into the mainstream:

  • Swipe up from the bottom opens the Start overlay, available from any context.
  • Swipe down from the top opens a multitasking view. Apps can be arranged into a split-screen pair by dragging them to either side.
  • Swipe in from the right opens Action Center, carried over from Windows 10.

Edge gestures scale better than persistent chrome on small, varied form factors, and they're already in users' muscle memory from the phones they hold every day.

What isn't here

Microsoft Edge on Cortana OS — the same picture-in-picture and Cortana-assisted browsing as the desktop version.
Microsoft Edge on Cortana OS — the same picture-in-picture and Cortana-assisted browsing as the desktop version.

No desktop mode. Apps can run in a split-screen arrangement, but there's no freeform windowing. Freeform windowing is the single biggest source of the complexity Cortana OS exists to escape. It implies Win32 compatibility, it implies file management, it implies the desktop metaphor the product is deliberately stepping away from.

No Live Tiles. Reporting on Windows Lite suggests Microsoft is dropping tiles in favor of static icons. I can understand why. Tiles have utility but come at a cost: the way you launch apps can look different every time you go to Start. Because of this rumor that Live Tiles might be dropped, I've done the same.

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