The super-munter is a variation on the munter-hitch. It creates a tremendous amount of friction and doesn't have one of the main problems of the munter-hitch, it doesn't tangle the rope. Indeed, the action of the rope as it goes through the super-munter twists the rope and then twists it back.
There are very few applications for the super munter (also sometimes called the monster munter) in normal climbing. Instead, the applications are more rescue oriented. This particular hitch provides so much friction that it is possible to lower two climbers -- one cradeling the other -- or perhaps a litter and a liter attendant in a SAR operation.
Super munters on two separate legs of a mountain rescue system, backed up by tandem prussiks make for an excellent redundant lowering system with limited equipment. And indeed, such a system would also pass the "Whistle Test." (The Whistle Test is a concept used in mountain rescue. The idea is that if everyone let go of their given strands at the sound of a whistle, the system would stop on its own and no one would get hurt.)
The problem with the super munter is that you have to anticipate that you are going to add the additional friction at the beginning of the operation. In other words, you have to tie the munter with the appropriate position of function, so that you can easily cross the break-strand over the load-strand and then clip it into the carabiner. If you did not do this right then a second option is to make a zooper munter.
This essentially requires a second carabiner behind the first, with the gate facing the spine of the first carabiner. To build the zooper munter, just bring the rope around the back and clip the second carabiner. You can see this in the second video which is a bit shaky since I was holding the camera and tying the knot at the same time.
The zooper munter allows you to create additional fiction without pre-planning. In many ways, this is a far more useful version of the super munter because it doesn't have to be pre-planned and -- even if the carabiner is situated correctly, you wouldn't have to open the gate.
Large amounts of friction are important when it comes to SAR operations and indeed, are super important when you are in a mountain rescue setting with limited gear...
--Jason D. Martin