The first handsets running Microsoft's rebooted Window Phone 7 will appear later this year, so now is a great time to get ahead of the development curve and examine the operating system's feature set. Charles Petzold, author of the upcoming book "Programming Windows Phone 7 Series," outlines five Windows Phone 7 features below.
1. Windows Phone 7 is a clean break
Charles Petzold: The bad news is that the Windows Phone 7 is a complete break from the Windows Mobile past, not only in name but in application programming interfaces. Of course, considering the lackluster market penetration of Windows Mobile, this break could also be regarded as good news. And once you start looking at the APIs for Windows Phone 7, I think the good news just keeps getting better.
2. Silverlight and XNA are both supported
Charles Petzold: Silverlight and XNA are rather recent programming interfaces, but they've both developed enthusiastic followings among developers. They're both part of .NET, they're both managed-code environments, and they both require C#. But there the similarities end. The Silverlight and XNA programming paradigms are quite different, and that makes a lot of sense, because there's likely to be different types of programs written for Windows Phone. Generally, we'll use Silverlight for applications and utilities, and XNA for games. I think the inclusion of both these programming environments on Windows Phone was a stroke of brilliance.
3. Windows Phone 7 has connections to the Zune and Xbox
It's now become apparent that the Zune HD was a sort of "rough draft" for Windows Phone. Both devices have the same type of OLED display, capacitance multi-touch, an accelerometer to detect orientation and motion, and the same user-interface look and feel. For developers, the Zune HD runs XNA 2D programs, so it provides an excellent platform for us to learn how to write XNA 2D programs for hand-held multi-touch devices. This is how I learned XNA 2D. What's missing with the Zune HD is a mechanism to actually distribute these games to other users except as source code.
Windows Phone goes beyond the Zune in supporting XNA 3D and Silverlight, but to a very real extent, Windows Phone is a Zune. Along with everything else, it's a digital audio and media player.
Web services are an important part of Windows Phone, and these web services include Xbox Live, which means that games for Windows Phone can access the user's avatar, achievements, and other information, and enable multi-user games.
4. Microsoft will run an apps marketplace
Charles Petzold: Microsoft will be hosting an application marketplace for Windows phone accessible through the desktop Zune software. It is my understanding that this marketplace will go live in late summer.
5. Windows Phone 7 has strict hardware requirements
Charles Petzold: The minimum hardware requirement for Windows Phone 7 is quite extensive. It's going to make development for the phone much easier than for the Windows Mobile platforms of the past. When writing programs for the phone, developers know they have at least a four-finger capacitance multi-touch display, and they have features such as an accelerometer and location services. Screen size is often critical for small devices, and Windows Phone is guaranteed to have only one of two screen sizes: 480 by 800 or 320 by 480. There might be some phone manufacturers who prefer a little more flexibility, but I think developers will be happy with the restrictions.