Looking at the images and format. I'd guess it's as simple as opening the shutter for a longish exposure and panning the camera on a tripod.
Maybe there's some complicated modifications to a panoramic camera like a Cirkit or Roundshot, or maybe a powered panning head to avoid banding, but there's no suggestion of that on the site. The only clue is the photo on the home page that seems to show a large format camera of some sort on a tripod being used.
For me the most successful part of the work is it's promotion ;-)