Windows 10 Mobile review: Windows on phones gets rebooted. Again.

One way or another, Microsoft has been promising Windows 10 Mobile for years.

References to "Windows Everywhere," the notion that some version of Windows could run on everything from PCs to servers to cars, can be found as far back as 1998, when Redmond was hawking Windows 98, Windows NT 4, and Windows CE. Per Paul Thurrott, the plan was conceived as "NT Everywhere;" the broader ambition of "Windows Everywhere" soon made space for the Windows 9x and Windows CE variants.

How the idea was expressed varied—in 2009, for example, Microsoft called it "Three Screens and a Cloud"—but the notion of having a Windows platform for any device has endured.

Over the last three years, that plan has become more concrete, with Microsoft telling developers to prepare for a world where apps can run equally well on a desktop, tablet, smartphone, TV/games console, holographic augmented reality headset, or even an embedded Internet-connected gadget.

Windows 8.1 and Windows Phone 8.1 were a step in this direction; Windows 10 and Windows 10 Mobile make it a practical reality.

In this review, we take a look at what Microsoft has delivered with Windows 10 Mobile. With so many of the included apps all but identical to their counterparts on Windows 10—even Cortana is shared across operating systems now—the focus will fall squarely on mobile—those things that Windows 10 Mobile does differently from desktop Windows 10.