I’m sure over the coming days and weeks we’ll be answering, over and over, the “why didn’t this ship first on Microsoft’s own phone” question. Our approach to the design of the Photosynth app hopefully provides some evidence that we very much think of Windows Phone 7 as brethren and inspiration, not to mention proof that Microsoft can make beautiful things. (Such a joy and a relief, after the previous generation of Windows phones!) If we could have shipped first on these devices, we would have. But the level of camera and low-level algorithmic hacking needed to make Photosynth work meant that, if we wanted to get this out as quickly as possible— and we surely did— we needed to do so on a platform that provided the necessary low-level device access. Windows Phone 7 doesn’t yet allow this for apps. It will soon. It’s worth keeping in mind that the first several generations of iPhone device and OS wouldn’t have allowed us to build this app either. For now, iPhone’s platform maturity— and of course the large number of people with iPhones out there— meant that it made sense for us to go for it.
At Bing we’re always interested in reaching as many people as possible, which means we’ll always develop for multiple platforms. But over time, we’ll be doing more and more of our early innovation on the Windows Phone.