Metro apps only available from Windows 8 store

Metro apps for the upcoming Windows 8 operating system will be available only through Microsoft's own store, the company has announced - and like arch-rival Apple's iTunes store for iPhone and iPad apps, it will cream off a whopping 30 per cent of every sale.

In a mirror of Apple's 'walled garden' approach, the now officially-titled 'Windows Store' will be the place where users can download apps running under Windows 8's Metro interface on Intel-based PCs and ARM-based tablets. The model runs counter to Google's more open approach, under which users can download apps for the search giant's Android OS from the web as well as from the official Android Market.

Speaking last week at the Microsoft Build conference, at which 5,000 Windows 8 prototype tablets were handed out to developers, Ted Dworkin, the Microsoft director in charge of the Windows Store project, said that the move was being made to ensure all downloads were safe and secure.

Like Apple, Microsoft also plans to approve every app submitted to ensure they are malware-free.

"We will examine every application that will be submitted to us [and] we will run a virus check and a malware check on every application," Dworkin said.

What Microsoft wasn't prepared to discuss, however, was its business model for the Windows Store.

"We are not going to spend time [today] on the specific store policies and the specific business terms," Dworkin told delegates at Microsoft's Build developer conference last week. "We will describe them in great concrete detail [later]. At the point when we're ready for [app] submission, that's the point at which you will understand what the specific store policies and business terms are."

But a Microsoft primer on the Store, spotted on the web by blogger Long Zheng and since revised, proved a little more enlightening:

"Following industry norms, developers pay a nominal yearly fee to upload apps to the Store, and receive 70% of the gross income from those apps (for paid apps and in-app purchases that use the default commerce engine)," the document said.

Interestingly, elsewhere in the primer Microsoft stipulates that developers must give users a five-device licence to any app, enabling them in principle to install it on a mix of tablets, PCs and Windows Phone 7 devices for a single price.

Among the Metro-based apps rumoured to be under development for the new Windows 8 OS is Metro Office, a port of Microsoft's best-selling productivity suite. The Store will also carry non-Metro devices built for x86 devices.