Although the two versions of Windows Mobile have a great deal in common, currently developers have to modify their Pocket PC applications to run on the Smartphone version, and vice versa.
However, Microsoft has been bringing these two versions closer and closer together, and with Windows Mobile 5.0 it will finally be possible for a developer to create a single application that will run on both the handheld and smartphone versions of this operating system.
According to John Starkweather from Microsoft’s Windows Mobile team, “With the addition of softkeys, a common CAB format, and application signing on Pocket PC in Windows Mobile 5.0 (used to just be for Smartphone), developers can rather easily build an application that targets both Pocket PC and Smartphone. In fact, we’ve already heard from some of our early 5.0 beta testers about certain applications that ran across both Smartphone and Pocket PC.”
The softkeys Starkweather mentioned are a feature that first debuted on the Smartphone version of Windows Mobile, but will soon appear in the Pocket PC version. They are a pair of buttons on the bottom of the screen whose functions change from application to application, and are controlled by a pair of hardware buttons below the display.
Another way that the two Windows Mobile versions are coming together is in screen resolution. Both now support QVGA (240 by 320 pixel) screens. However, it will soon be possible for developers to create a single application that runs on devices with screens as small as 172 by 220 pixels, QVGA devices, and even VGA (640 by 480 pixel).
Of course, not all applications will be written this way. Many developers will choose to optimize their applications for a specific form factor and screen resolution.
However, Microsoft believes this will become less common in the future. “Moving ahead, we’re encouraging developers to develop UI [User Interfaces] that can adapt to different resolutions and orientations as well as input mechanisms, much like desktop applications do today,” said Starkweather. “This will become increasingly important as the obvious definitions/lines between a PDA and a phone continue to blur.”