An excellent panorama, right up there with the best!
I shoot panoramas too.. he may have used Gigapan (that pano appears to use the gigapan viewer) or Kolor APG to stitch, they both offer a standalone stitching service, a normal home computer would be insufficient, panos containing that many images need obscene amounts of RAM. I recently shot a 1600-image panorama (
Cusco ) shot with my Pentax K-r and gigapan Epic 100 rig, it stitched on my laptop with only 2gb RAM, but I used gigapan's Efx software, which can handle 2000-image panoramas, but lacks cropping, anti-ghosting, anti-haze and a bunch of other features. Any other Pentaxians interested in this? Maybe start a Pentaxians Panorama section. Pre-processing the K-r's bracketed shots with Photomatix before stitching gives some interesting results:
Plaza de Milla, Merida