At least four sessions are devoted to unpacking the technical details of Windows Phone 7, which is actually the user interface layer atop the underlying Windows Embedded CE 6.0 R3 kernel, to manufacturing in September 

Despite the radical new phone UI, software developers will rely on familiar Microsoft tools and technologies for writing the applications that exploit it, including .NET, Silverlight (see below) and Microsoft Expression Blend 3, and the gaming development environment XNA Game Studio. Windows Phone 7 incorporates a new application model, new input models (including multi-touch), APIs to access phone features and applications, and new Web services.

Microsoft recently announced the of "Windows Mobile" to "Windows Phone Classic" and has confirmed that existing mobile applications to Windows Phone 7. For some developers, that's bad news. "By dropping backward compatibility you have basically just killed Windows Mobile, and since your new platform will be very unfriendly to enterprise and is years behind developer and consumer adoption, you have basically killed Microsoft's mobility ambitions," one developer, surur, commented on a Microsoft .  

But others are ready to embrace that radical break with Windows Mobile. "If you honestly won't look into a new technology because it might not support something you wrote seven years ago, you're in the wrong field," commented Ian Muir, in the same thread.

Given the emphasis on Microsoft tools and technologies, one other issue is to what degree the Windows Phone 7 platform will be open to outside tools and technologies.