The announcement, made at the MIX10 developers' conference in Las Vegas, didn't specify which apps will be offered for the successor to the current Windows Mobile operating system, or the price ranges. But the company said its Silverlight multimedia technology, a competitor to Adobe Systems' Flash and AIR technologies, will be the basis for "rich Internet application" development. Flash, ubiquitous on the web, is supported on a wide variety of mobile devices -- with the notable exception being Apple's iPhone and iPad.

XNA Support

Microsoft also said Windows Phone 7 supports XNA programming tools for game development. A software development kit for Phone 7 application development was released last week.

While virtually all mobile platforms now have app stores, Microsoft is taking a few cues from Apple. For instance, the company said all Phone 7 apps in the Windows Marketplace for Mobile store must be approved first by Microsoft, as Apple requires for its App Store.

However, Microsoft has told news media it will make decisions about applications more expeditiously than Apple, which should please developers. It also said that trial versions of applications will be required, so customers can try before buying.

The Windows Phone 7 Series platform was unveiled in mid-February at the World Mobile Congress. Microsoft CEO Steve Ballmer made the presentation, which the company touted as bringing together for the first time Xbox LIVE games and the Zune music and video experience on a mobile phone. Devices based on the platform are expected to be on the market by the Christmas holiday season.

Phone 7 as a Gaming Platform

Microsoft has said it is taking a "fundamentally different" approach to software with Phone 7. For example, "live tiles" on the Start screen are dynamically updated with real-time content , instead of simply serving as static doors to an application.

The company's Bing search engine is also being integrated into Phone 7 devices in the form of a dedicated hardware button. The interface uses a variety of new approaches, including categorizing content, applications and services into six hubs -- People, Pictures, Games, Music + Video, Marketplace and Office.

IDC Program Director Al Hilwa, who is attending the MIX10 conference, pointed out that Microsoft is integrating several major platform technologies into Phone 7. "It's interesting that they've chosen a web-based technology, Silverlight, as their main environment," he noted. Additionally, Microsoft said it is committed to extending Silverlight to other platforms, such as Symbian.

He also noted that the support for XNA indicates that "Microsoft is making Phone 7 its mobile gaming platform." This means, Hilwa said, that Xbox games should be able to be as readily adapted for mobile devices as, say, iPhone apps can be adapted for the iPad. "Essentially, it will be the same application," he said, but modified for different display and control options.

Hilwa said that, while Microsoft is going to exercise more control over apps, it probably won't be quite as tight as Apple's -- and certainly not as loose as Google's over Android apps. Instead, he said, "their degree of control will probably be somewhere in the middle."