Microsoft's plans with Xiaomi to offer a Windows 10 Technical Preview ROM for the Xiaomi Mi 4. A few more details have come to light since then, along with a photograph showing Microsoft's operating system running on the Chinese OEM's Android phones.
TechCrunch writes that from Xiaomi's perspective, this is emphatically not a partnership with Microsoft. Rather, Redmond is running a kind of experimental trial to gain feedback from Chinese users and enhance the experience of running Windows 10 for phones in China. Xiaomi promotes the use of custom ROMs on its devices, so a Windows 10 ROM is simply just another operating system option rather than an indication of any desire on Xiaomi's part to make or ship Windows 10 phones.
Microsoft released an official statement with somewhat different verbiage. From Microsoft's perspective, there very much is a partnership, though the Windows 10 ROM is still pitched as an information-gathering exercise and nothing more:
As part of the Windows Insider Program, Microsoft will partner with Xiaomi to offer Windows 10 free downloads to a select group of Xiaomi Mi4 users. Xiaomi Mi4 users will get the ability to flash their phones with the new Windows 10 OS and provide feedback to Xiaomi and Microsoft on their experience. This partnership will allow Xiaomi and Microsoft to get direct user feedback and continue to improve the experience for China. Microsoft is thrilled to see Xiaomi embracing Windows 10 and offering this great value to their customers. We’re excited to see the feedback we receive from this audience.
Xiaomi is a leading phone manufacturer in China undergoing significant global expansion. We are excited to partner with them in China and jointly gather feedback from Chinese users on their experience with Windows 10 to jointly collaborate on product and services development for the platform.
Availability will be announced in the months to come.
A photograph of the phone with the software has been released on the MIUI forum, and it looks much as you'd expect: Windows 10 for phones on a Mi 4. This just happens to be the highest specced Windows Phone/Windows 10 for phones device there is. With a 5-inch 1920×1080 screen, quad core 2.5GHz Snapdragon 801, 3GB RAM, 13MP rear and 8MP front cameras, and a large 3080 mAh battery, this phone matches or surpasses the specs of any of the operating system's "real" hardware.
In some ways, the most surprising part of this exercise is that it took so long. Microsoft consciously and deliberately changed the Windows Phone hardware requirements to ensure that it could run on Android-spec hardware. The HTC One (M8) for Windows brought Windows Phone 8.1 to Android hardware, but that phone had the operating system choice baked in at the factory. The Mi 4 will be the first phone to enable end-user switching, something we suspect will greatly appeal to all manner of tinkerers and inveterate fiddlers.