It probably just takes a few burst shots, and do classic stitching (?).
I don't know what you mean by classic stitching... I can say the results from Panoman aren't exceedingly good, and it's especially bad if you move the camera vertically. It does claim to do some exposure correction.
Very interesting indeed! You can take burst shots at high ISO, and create a single denoised image. Are there open source solutions? Superresolution is interesting too.
It's one of several programs that work with stack of images - a popular one here is CombineMZ, mostly used for DOF stacking, but it should have no trouble doing noise reduction by stacking. It's open-source, though Windows-only (works in WINE).
Another very capable open-source tool is ImageJ, which is written in Java and works on both Windows and Linux. It comes with powerful functions to deal with image stacks, although to do depth-of-field stacking as well as
image stabilization you need
plugins that aren't included - but they're mostly open-source, too.
For just noise reduction, again you can just use the built-in stack averaging function, perhaps with the help of the image stabilizer if you've not shot on a tripod.
For super-resolution, I don't know of an ImageJ plugin... but "the" open-source super-resolution tool is
ALE. Be warned that it tends to be, uhm, slightly slow...
For other programs, I suggest looking at
this Wikipedia article including the "See also"'s.
Some quick Googling also gave me
this page, which has another list.
Note that even though Google can often give you the impression that a program can only do one sort of stack manipulation (DOF, or super-resolution, or, or), more often then not, they can do other kinds, too, as some of the techniques are pretty strictly related.