Sources: Silverlight The Platform For Windows Phone Apps

Instead of throwing more resources into the fading star of Windows Mobile, Microsoft will rally its developer army to build Silverlight mobile applications and quickly establish Windows Phone as a viable platform. Microsoft developers have been anticipating the move for some time, and it makes sense for Microsoft on a number of levels.

Silverlight, which is based on .Net, lets developers reuse desktop application code to build applications for mobile devices and the Web. Microsoft's Visual Studio and Expression IDEs allow .Net developers to work with Silverlight using tools with which they're already familiar.

For developers, being able to write one code base in managed code and have it run on multiple platforms and numerous form factors and devices will be a major advantage.

"Native Silverlight on Windows Phone is going to open it up to a huge amount of developers and create a large ecosystem for building and acquiring applications," said one source, who requested anonymity. "We have been waiting for this for a long time."

With Silverlight running natively on Windows Phone, developers can get started building apps with the Windows Phone SDK even though devices won't hit the market until the latter part of the year. "The best thing about Silverlight is that you can start designing applications before ever touching or seeing a Windows Phone device," said another source, who also requested anonymity.

Asked for confirmation of Silverlight's role in Windows Phone 7, a Microsoft spokesperson offered the following statement: "While we are not sharing details about the Windows Phone 7 Series development platform or marketplace publicly at Mobile World Congress, you can expect much more information about the developer tools and opportunity to come at MIX in March."

Microsoft has been trying to raise Silverlight's profile for years, and its deals with NBC have made Silverlight the official Web multimedia player of 2008 Summer Olympics in Beijing and the 2010 Winter Games in Vancouver.

However, Silverlight has been unable to make much headway against the more entrenched Adobe Flash, despite being widely regarded as a superior technology. On Monday, Microsoft CEO Steve Ballmer said that while the first iteration of Windows Phone 7 won't support Flash, it's something that Microsoft may consider for future versions.

In the meantime, Microsoft is readying Silverlight for its biggest star turn yet. As the development platform for Windows Phone, Silverlight will occupy a far bigger stage that it ever has. And if the plan succeeds, Silverlight could end up going down in history as the technology that helped save Microsoft's mobile business.