From the "Hey, everybody else is doing it" department:
The folks in Redmond pushed out their first application for the iPhone Saturday, a mobile version of its Seadragon image viewer that lets users deftly navigate large images. Here's a video of the app in action from one of its developers at Microsoft's Live Labs.
What's significant here isn't the feature set – pinching, dragging, and tapping on images has been present on the iPhone from day-one – but that Apple rival Microsoft has in a sense extended an olive branch with its release.
Why develop software for a rival's platform? Microsoft Live Labs group product manager Alex Daley told Techflash that designing for the iPhone made sense because it's the most widely distributed phone with a graphics processing unit (GPU):
Most phones out today don’t have accelerated graphics in them. The iPhone does and so it enabled us to do something that has been previously difficult to do. I couldn’t just pick up a Blackberry or a Nokia off the shelf and build Seadragon for it without GPU support.