How Windows Phone apps could run on Windows 8

A new leak gives the first real glimpse of what to expect in a special Windows 8 interface for tablets, and shows how Microsoft could unite Windows and Windows Phone through a shared catalog of apps — attempting to rival the iPad and Google Android devices while standing by its flagship PC operating system.

After breaking the news about plans for a “ribbon” interface in Windows 8s, authors and bloggers Paul Thurrott and Rafael Rivera today followed up with screenshots of Internet Explorer in a special Windows 8 tablet interface known internally (and now externally) as “Immersive.” As they write in that post, there’s not a whole lot to see in this early build — but what they found under the hood is more interesting.

In a separate post, Rivera and Thurrott detail a new Microsoft PDF reader apparently planned for Windows 8, noting that it’s the first app they’ve examined that uses a new “AppX” application package type. What does that mean? From the post …

AppX is a new type of packaged application model in Windows 8, and it very closely resembles Windows Phone 7 application packages. For this reason, we surmise that the AppX application type could be common to both Windows 8 and Windows Phone 8 (codenamed “Apollo”), providing developers with a way to write applications that target and can transition between a variety of devices, including traditional PCs, tablets, and phones.

Outside developers were key to the early success of Windows, as memorialized by CEO Steve Ballmer’s legendary “developers, developers, developers” chant. But Apple and Google have beaten Microsoft at its own game so far in the mobile industry, with large libraries of apps from third-party developers.

It’s going to take some sort of unified development strategy, like this, to help turn things around for Microsoft. With Windows 8 due expected sometime in 2012, the only question is whether it will be in time.