At Microsoft's Windows Phone Summit in San Francisco this morning, Redmond officially announced Windows Phone 8. The company confirmed what we've suspected for many months now: Windows Phone 8 will be built around the same core components as Windows 8.

The current Windows Phone 7.5 operating system is built on Microsoft's Windows CE platform, designed for embedded systems with tight memory constraints and slow processors. Windows Phone 8 will instead be built on the Windows NT platform, and in so doing will inherit its much richer feature set: support for multicore processors, robust file systems, extensive device driver support, a capable multimedia framework, and more.

With the new kernel, Microsoft is also enabling the creation of native code applications written in C++ for the first time on Windows Phone. In version 7.5, all applications are developed in C# or Visual Basic .NET and compiled to platform-independent bytecode. While this has proven easy to use and attractive to many developers, it makes it hard for game developers to eke out all the performance the hardware can offer. It also precludes the use of useful libraries that developers on iOS, Android, and Windows can take advantage of.

Windows Phone 8's native code support addresses both issues. Native code development will produce programs that run directly on the ARM processors that Windows Phone supports. This should boost performance, and will greatly extend source code compatibility with other platforms.

While this has particular appeal to game developers—they'll be able to more easily port 3D engines based on Direct3D to the phone platform—they won't be the only beneficiaries. Microsoft said that embedded database engine SQLite, for example, will be available for phone developers. Though widely used in iOS programs, SQLite has been hitherto unavailable on Windows Phone (as it's written in C). The inability to use libraries such as this has been one of the biggest pain points for Windows Phone developers, and the new native code support is likely to be warmly welcomed.

The native code support won't cater to every possible demand, however. Notably, OpenGL ES, the 3D API used by iOS, won't be included, and so 3D applications will have to be rewritten to use Direct3D.

Though the core components will be shared, Microsoft did not go into detail about which APIs would be available to phone developers. Windows 8 introduces a new API named WinRT that is designed for the development of Metro-style applications. Windows Phone 8 will support some pieces of WinRT, along with some unspecified subset of Windows 8's security, networking, media, audio, and sensor APIs. Longer term, the company plans to align the two platforms ever more closely.

Windows Phone will also contain unique APIs of its own where it makes sense to do so. For example, the current platform has two user interface constructs called Panorama (which breaks up a larger application into a set of discrete screens) and Pivot (which provides filtered views of data) that are tailored to the constraints of small-screen devices. These will continue to be a feature of the phone platform.

With the switch in kernels, Microsoft is extending the Windows Phone platform to support processors with two, four, or potentially even more cores. Windows Phone 8 will include full device encryption based on Windows 8's BitLocker technology. Removable storage on SD cards will also be included in version 8. The browser will get a corresponding update, with Windows Phone 8 including Internet Explorer 10.

In addition to improving the capabilities of the operating system today, Microsoft believes that the transition will increase its ability to keep the platform abreast of new hardware developments in the future. Device drivers, for example, should be substantially, if not completely, portable between desktop Windows and the phone; in turn, this should allow Microsoft and third parties to more rapidly incorporate support for new sensors, wireless networking standards, and so on.

Early fruits of this easier hardware support will include support for new GPUs along with a couple of new screen resolutions (1280×768 and 1280×720, in addition to the current 800×480), and support for NFC chips.

Microsoft is describing the kernel change as another "reset," as significant in some ways as the abandonment of Windows Mobile 6.x and the development of Windows Phone 7. While the improved hardware support will please OEMs competing on spec sheets and the new native code support will please developers, it does come at some cost: there won't be any ability to update current Windows Phone devices to the new operating system. Windows Phone 8 will retain full compatibility with all current Windows Phone 7 applications, but current users will never be ushered into the NT-powered future.