Compact Armor is a revolutionary development in starship armor created by NanoTech Industries.  CompactArmor is the product name, while Compact Armor is the classification of the armor.  CompactArmor is the only item in it's class.

Compact Armor is created when the molecules in the armor are compacted on a nano level, effectively removing the empty space between molecules resulting in a super-dense and massive material that excels at the armor-to-space ratio.  A three-inch sheet of Hardened Steel can be compacted into a sheet of CompactArmor that has the same dimensions as the original plate of steel, but has a greatly increased pound-for-pound strength at the cost of a noticeably higher weight.  The process of compacting the armor allows for the molecular implant of other molecules as well and it is typical for several layers of compacted depleted uranium or other materials to be added into the original object as the material is more or less reconstructed at a nano level instead of simply compacted.  This method also allows for insulating material such as rubber to be mixed into the metal and while it doesn't necessarily increase the strength of the armor, it increases its resistance to things like electricity.

Several plans for compact body armor have been proposed, but were eventually rejected as creating CompactArmor for soldiers that would cover all of the necessary vitals and more while being able to absorb shells up to and including 20mm in size would weigh well over 300kgs.  There is currently a proposal on the table for a CompactArmor Powered Exo-Suit.