SUL

SUL - the consensus describes this method of backpack travel as "super ultralight" and falls into the weight category of 5 lbs of gear or less. That's right! 5 POUNDS. Frankly, it takes perfect weather and severe gear "discipline" to get outdoors safely with a backpack this light. Most of us hangers would only be able to reach this pinnacle by shaving off mere ounces by choosing minimalist gear and taking measures to go camping without usual items like a stove, by leaving the tarp and raingear behind, perhaps even all luxuries must stay home. In an odd twist, this type of hike and gear selection takes just as much preparation as something like a 4 day trip into the Wind Rivers. Less gear, one would think, takes less preparation/concentration/motivation. Not so, if you are asking. I think a pack this light takes skill, dedication, and motivation that exceeds the usual traditional pack and also the lightweight/ultralight pack. To get weights down to 15 lbs is not a difficult task, there is gear out now even in the mainstream that can do this for you, at little cost, to boot.
Getting down to 10 lbs or less requires sincere observation of gear choices. You must take a leap to define what is essential and what is not.
SUL, on the other hand, is basically bringing only what you need to Survive! No coffee press here, no GPS and no Thermarest Chairs. The rewards of hiking with such a light pack is in and of itself, the biggest luxury. Im about to take off for an overnighter with a pack weight that barely tips 4 1/2 pounds. For a hammock hanger, I do admit this is a bigger challenge.. as many can sleep on the ground with a thin pad, the hanger adds weight to his kit with all the neccessary items demanded by this style of camping. that being said, here is a short intro to my big 4 gear list.. and anything of consequence that one might be interested in:

pack - 10.3 oz MLD Burn (by SUL standards, 10oz is hefty)
hammock - WB traveler, whoopies and toggles, 9.1oz
tarp - Zpacks cuben 11x9, stakes and tensioners, 8.9oz
quilts - my own breeze @10.3 and my tq at 13.6oz, respectively

by making everything usable for at least one task, (nothing here is unused) and several of my items are dual duty or even triple duty (such as cuben tarp becomes rain poncho if needed) you can get away with very limited gear and very light weights. Food will be all self-prepared, no stove, and high calorie. A little scotch will be along in case i need it ;)