Puty simply, Photosynth allows you to take a bunch of photos of the same scene or object and automagically stitch them all together into one big interactive 3D viewing experience that you can share with anyone on the web.

Photosynth is a potent mixture of two independent breakthroughs: the ability to reconstruct the scene or object from a bunch of flat photographs, and the technology to bring that experience to virtually anyone over the Internet.

Using techniques from the field of computer vision, Photosynth examines images for similarities to each other and uses that information to estimate the shape of the subject and the vantage point each photo was taken from. With this information, we recreate the space and use it as a canvas to display and navigate through the photos.

Providing that experience requires viewing a LOT of data though-much more than you generally get at any one time by surfing someone's photo album on the web. That's where the unique Seadragon technology comes in:

Delivering just the pixels you need, exactly when you need them.
It allows you to browse through dozens of 5, 10, or 100 megapixel photos effortlessly, without fiddling with a bunch of thumbnails and waiting around for everything to load.

Microsoft delivers this immersive viewing experience to users on multiple operating systems by tapping into the power of Silverlight, Microsoft's rich web application technology.