Yesterday, I wrote about some of the new features in Windows Phone 8 based on a leaked version of the upcoming Windows Phone 8 SDK (software development kit). Today, I’d like to provide a similarly high level look at some of the developer documentation that accompanies the SDK.

To be clear, I simply haven’t had a lot of time to examine this stuff, so this won’t be a complete/exhaustive list of information about Windows Phone 8. I hope to spend a lot more time with the SDK in the days ahead, however.

Here’s what I’ve seen so far, interspersed with some information I’ve obtained elsewhere for context.

Windows Phone Runtime. The SDK documentation notes that Windows Phone 8 uses “a phone-specific version of the Windows Runtime,” or WinRT. This is going to confuse people, but the short version goes like this: While Microsoft wishes to stress the similarities between Windows 8 and Windows Phone 8 development by calling each set of APIs by the same name—WinRT—the truth is that they’re similar but different. There was a push to call the Windows Phone version something different—like Windows Phone Runtime, or WinPRT—and traces of this language can still be found in the documentation. My understanding is that this name won’t continue, but I think differentiating it from WinRT makes sense.

Lock screen extensibility. This is new information, I believe: Third party apps can now register as the lock screen wallpaper provider, and can be included in the lock screen notification area. These notifications can include a 24 x 24 app icon, an app count, and/or text of some kind, each of which is pulled from the app’s tile.

Screen resolutions. While it’s well understood that Windows Phone 8 will support three different screen resolutions—WVGA (800 x 480), WXVGA (1280 x 768), and 720p (1280 x 720)—I received a lot of questions about how or whether this will make developers’ lives more difficult. But there’s no worry here, as Windows Phone (like Metro on Windows 8) auto scales intelligently. “Existing Windows Phone [7.x] apps run on WVGA, WXVGA, and 720 phones without changes, and scale [automatically], with crisper text and vector art on the higher-resolution displays. App developers should consider producing high-resolution versions of their apps using higher-quality bitmap assets, which look beautiful on the high-resolution displays and scale down with comparable quality to WVGA.”

resolutions

Wallet. Microsoft announced Wallet at its Windows Phone Summit back in June, but the documentation provides a few more details. (I also wrote about Wallet in Windows Phone 8 Unveiled.) “[Wallet lets] users directly purchase Marketplace content using stored payment options, such as a credit card, gift card, or PayPal account, instead of relying on the mobile operator to bill them later. The wallet also enables ‘contactless’ NFC-based payment using Windows Phone 8 Developer Preview phones that feature NFC hardware … by ‘swiping the phone’ across NFC radio devices that can identify the payment options stored on the phone and process transactions instantly.” And Wallet is extensible by third party apps.

New camera and lens apps. If there’s a weak link in the Windows Phone story today, it has to be the camera. But Microsoft is correcting that in Windows Phone 8 with an all new Camera API that offers functionality such as “camera parameter configuration, such as ISO speed and exposure; real-time access to the phone’s video stream; Lenses, which are special camera apps that can provide enhanced camera functionality such as effects, filters, and computational photography; and multi-frame capture for creating new types of camera experiences and imagery.”

Removable micro-SD storage card support. We know that Windows Phone 8 will formally support micro-SD cards for the first time. The SDK notes that SD cards are “hot swappable” and that developers can access read-only APIs for accessing the contents of this storage. This includes a new File I/O API as well as—get this—Win32(!) storage API access too.

Nokia Maps. Nokia’s Maps solution is replacing Bing Maps in Windows Phone 8. That said, developers can continue to utilize the Bing Maps APIs. “Nokia Maps features beautiful cartography, more complete and accurate map data, a new 3D mode, and hardware-accelerated rendering for smooth performance,” the documentation notes. “A new WinPRT-based location API also accompanies the new Nokia Maps control and provides functionality new to the Windows Phone platform such as generating driving directions with an API call so that they can be included in your app.”

New Proximity API. When you think of “proximity” with a smart phone, you typically think of a proximity sensor that determines whether the device is being held against your face so it can behave accordingly. But Windows Phone 8 includes a new Proximity API for apps so that they “can establish a connection [with] another instance of your app on another, nearby, phone.” If the phone has an NFC chip, NFC tap can be used to make this connection too.

New Bluetooth capabilities. Windows Phone users have often expressed frustration with the platform’s lackluster support for Bluetooth profiles. Windows Phone 8 includes some new Bluetooth APIs that provide support for app to app communication, app to device communication, and peer discovery (where a pairing is not required).

New Launchers. Windows 8 includes a few new Launchers, such as Save Appointment Task, Map Downloader Task, Maps Task, and Maps Directions Task. Launchers provide a way for an app to launch another built-in app; some that come with Windows Phone 7.x include Email Compose Task, Phone Call Task, and Search Task.

More soon!