Photosynth is one of the most exciting programs I've seen in a long time. It takes a group of photos, typically of a single geographical location, but possibly taken at different times by different people, analyses them for similarities, and then stitches then together into a smooth-flowing, pseudo-3D panorama. It's really great. Just two problems. One: it won't run on GNU/Linux; and two: it's from Microsoft, and so is unlikely ever to do so.

My question is this: Why didn't the free software community come up with Photosynth first?