The above is an equirectangular projection of a full spherical panorama. You can view it from the inside here.
In the past few days, libpano has seen the addition of four new projections. I added them to hugin’s experimental version in the subversion repository.
Panini is credited to Bruno Postle and Thomas K. Sharpless. It was added to libpano13 by Daniel M. German, and it is probably the most interesting of the new projections. It replicates the perspective of vedute, stunning detailed large painting with a very broad field of view.
Architectural is an idea of Daniel M. German. A hybrid mix of Miller (which is almost conformal) on the top half and Lambert Equal Area on the bottom half. It presumes the space around you (in the bottom half of the pano) is less important than the space above the horizon, uses a smaller surface than the Equirectangular while giving more space to the top half.
Jim Watters committed the last two, which are fisheye-like variations – the orthographic and equisolid projections.