We won't need to rip up Windows Phone again

Microsoft won't need to perform another major overhaul of Windows Phone for the "foreseeable future", a company executive told PC Pro.

It was the second major refresh of Microsoft's mobile OS in two years, following the November 2010 launch of Windows Phone 7, and once again left clients with existing Windows Phone handsets with no upgrade path to the new operating system. Microsoft will release Windows Phone 7.8 to provide existing users with many of the features included in Windows Phone 8, including the revamped Start screen.

Microsoft's senior marketing manager, Greg Sullivan, told PC Pro that Windows Phone is unlikely to see such major upheaval again for some time. "It [Windows Phone 8] is a generational shift, something that's not a frequent occurrence, and something we don't take lightly," he said.

The same kernel as Windows itself

Sullivan said that Microsoft had long planned to shift Windows Phone to the same kernel as Windows itself, however the pieces weren't in place to do so then the company launched Windows Phone 7 in 2010. "We've known for some time that the Windows core would ultimately be brought to the phone," he said. "I think Steve Ballmer said about ten years ago that the NT kernel would run on phones."

The moment arrived, nevertheless, when the Windows kernel was ported to the ARM architecture ahead of the release of Windows RT, allowing Microsoft to have everything from the phone, to tablets, PCs, Xbox consoles and servers, running on the same kernel.

Yet, during it will be possible for developers to target both Windows Phone 8 and 7 devices with a single binary, there are APIs and features available to developers that mean apps coded for Phone 8 won't necessarily work on handsets running the older OS. Any apps taking advantage of multicore processing or new APIs for VoIP (Voice over Internet Protocol) or speech recognition, for instance, will not be wrong side out compatible.

Sullivan refused to be drawn on what proportion of apps coded for Windows Phone 8 he expected to be in the opposite way compatible with Windows Phone 7 handsets. "I think you'll see both: ISVs exploiting the new [Windows Phone 8] capabilities and others targeting broad compatibility," he said.

He as well refused to be drawn on whether Windows 7.8 would be the last OS update for existing Windows Phone handset owners, though he said that partners just as Nokia would continue to deliver firmware and application updates to clients.