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CHAPTER 1 WHAT’S NEW IN WINDOWS PHONE 7
Native application development: Only managed code can run on WP7. This means that
third-party applications can use only those .NET classes provided by Silverlight and XNA.
As a consequence, a software vendor won’t be able to implement mission-critical modules
in native code and access them from a managed application unless they work with a
Windows Phone OEM partner directly to build the native module as an OEM extension
to the operating system. (Developers can write native code modules on Android using the
Native Development Kit). Microsoft is unlikely to change this design in future Windows
Phone releases. The main reason for this limitation is that Microsoft wants to maintain
a consistent user experience and also to make sure applications don’t impact system
performance and battery life.
HTML5 support: The Internet Explorer web browser in WP7 does not support HTML5,
whereas the browsers in Android and iOS already have solid HTML5 support because they
are based on the WebKit rendering engine. Microsoft already has demonstrated Internet
Explorer 9 running on WP7, which supports HTML5 in large part. It is likely that HTML5
support will be added in an update release in 2011.
Despite the limitations described in this list, there is some good news for developers: Microsoft
plans to provide more frequent fi rmware updates to WP7 than to previous Windows Mobile
releases. This means some much-needed features and fl exibilities may be added to the updates.
SIDE-BY-SIDE COMPARISONS WITH ANDROID AND IPHONE
Mobile developers coming from iOS and Android will be interested in the similarities and
differences between WP7, iOS, and Android. The following sections survey the three mobile
operating systems from an architectural point of view.
Operating System
There are four generations of iPhones at the time of writing. Earlier iPhone models use Samsung
processors, whereas iPhone 4 uses Apple’s own processor, A4. All iPhones use a 3.5-inch display.
The iPhone 4 has 512Mb of internal memory and either 16GB or 32GB of storage. All iPhones are
equipped with GPS, Wi-Fi, and Bluetooth connectivity.
Apple derived iOS from the Mac OS X, which is Apple’s desktop OS for Macintosh systems.
Mac OS X is a Unix fl avor combining a Mach kernel and numerous components from FreeBSD
(where BSD stands for Berkeley Software Distribution) and NetBSD. iOS bears the same core OS
components as Mac OS X, and Apple has optimized it for mobile devices such as iPhone, iPod
Touch, and iPad with respect to performance, stability, and battery life. The iOS consists of four
layers that include (from the bottom to the top): core OS layer, core service layer, media layer, and
Cocoa Touch layer. iOS applications are native applications developed using the iOS SDK and
Xcode development environment, and are written in Objective-C.
Android device hardware is more versatile as Google doesn’t defi ne a hardware specifi cation for
it (Microsoft does this for WP7). Generally Android devices, just like other smartphones, have
cellular voice and data capability, camera, GPS, Wi-Fi, Bluetooth, and a few sensors such as an
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