MOLLE packs were first introduced for U.S. Army and Marine use in 2001, but it was not until 2003 that they came into widespread use in Afghanistan. MOLLE was developed to replace ALICE, or All-purpose, Lightweight, Individual Carrying Equipment, according to the U.S. Army Natick Soldier Systems Center. ALICE relied on metal clips for attaching components to load-bearing equipment. The attachments often came loose.
MOLLE consists of a load-bearing vest with a butt pack, and a backpack with a sleeping bag compartment that attaches to an external frame. The vest is always worn, and the external frame attaches to the waist belt of the vest. MOLLE heavy-duty nylon straps support the weight over the shoulders and around the waist. There are also MOLLE straps that are part of the Pouch Attachment Ladder System or PALS, according to Olive-Drab.com.
PALS, a component of MOLLE, consists of a grid of interwoven horizontal straps or webbing attached to the pack or vest at 1.5-inch intervals. There is also a 1-inch distance between every horizontal row of straps. Components like packs and pouches have attachment straps that the soldier threads vertically through the webbing and snaps together. According to BAESystems.com, additional accessories which can attach to the webbing include a hydration system and pocket sets for specialized purposes, like medical use.
Whereas ALICE came in two sizes, MOLLE shoulder and waist straps allow a soldier to adjust the load to the length of his torso and distribute the weight evenly across the torso, and transfers some of the load to his hips. This makes the load more comfortable to carry. MOLLE straps allow a soldier to detach unneeded components before a given mission and reattach them when he returns. He also doesn't have hard metal hooks or clips digging into his body.