Microsoft is officially back in the smartphone game with the long-rumored Surface Duo.

The folding smartphone, which runs on Android, will go on sale during the holiday 2020 season.

Rumors have been flying about a Microsoft smartphone for years after the company sunsetted its own mobile operating system.

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Somebody look outside to see if the pigs have started flying yet, because on Wednesday, Microsoft officially announced the Surface Duo — a smartphone that's been rumored for many years, but which seemed to be only a pipe dream when the company officially sunsetted the Windows 10 Mobile operating system.

The Surface Duo is a dual-screen, foldable phone running the Android operating system that Microsoft says is designed for productivity and made to integrate with Windows.

"Make no mistake, this product is a Surface," Microsoft hardware boss Panos Panay said at a Surface reveal event.

There have been too many rumors of this device, or one like it, to recount here. It was thought to be coming out in 2016, before it faded into the background. Many Microsoft-watchers, including your humble correspondent, thought it was fated to forever be vaporware.

The bad news is that it's not coming out until the 2020 holiday season, so we'll have to wait a little longer.

The reason for the delay, Panay indicated on stage, is to help developers optimize their apps for the new two-screen interface. Notably, it's a little different from existing foldable smartphones like the Samsung Galaxy Fold — there's a clear seam between the two screens, making it more about multi-tasking than having a single, large display.