Microsoft currently curates three environments -- Xbox, Windows 8, and Windows Phone 8 -- all of which have different development libraries and require a lot of work to port from one to another.
But Microsoft hopes that with the Xbox One and Windows/Windows Phone 8.1 releases, these platforms can be brought together to the extent that a developer can make single app that can run on all three devices. That's the vision new Windows Chief Terry Myerson -- formerly the head of the Windows Phone unit -- is pushing as Microsoft reorganizes following the acquisition of phonemaker Nokia and the pending departure of CEO Steve Ballmer.
At the a Financial Analysts meeting, he remarked:
The first of those beliefs is that we really should have one silicon interface for all of our devices," he said. "We should have one set of developer APIs on all of our devices. And all of the apps we bring to end users should be available on all of our devices. We want to facilitate the creation of a common – a familiar – experience across all of those devices, but a fundamentally tailored and unique experience for each device. We should have one set of developer APIs on all of our devices.
Of course it may be impossible to escape some sorts of optimizations for more serious apps; after all Windows Phone is a very different screen size, while Xbox has extra media and gaming hardware resources.
Some are surprised that given Microsoft's push of various apps including the Office Suite to the cloud that it still lacks a single unified app store for its tablets and smartphones. Apple already has such an app store. Microsoft might be able to follow a similar model to Apple in order to deal with the screen size problem -- allowing phone apps to run on the tablet, in upscaled form -- while making higher definition apps tablet/PC exclusive.
It's important to understand that at this point it's just talk -- we have no idea when Microsoft's unified environment will actually be ready for the market. But Microsoft already has a unified interface (the Modern UI, aka "Metro UI") across all of its upcoming devices, so we're not that far off. Microsoft's many developers should prepare themselves for this shift.