A couple of years ago, Marvel put out a one-shot called "The Iron Manual." In it, everything readers ever wanted to know about Iron Man (at the time) could be found, including what the famed suit is made of. Although Tony Stark's suit is purported to be made of thousands of individual, artificial cells in the comics, an American engineering firm in Utah is taking a different approach in building the first operational exoskeleton armor at the behest of the Department Of Defense.

On the campus of the University of Utah, robotics and engineering firm Sarcos is quietly working on the powered exoskeleton. Work began in 2000 when Sarcos accepted a grant from DARPA (the Defense Advanced Research Projects Agency) to develop an exoskeleton for potential military application.

Popular Science first covered the XOS armor back in 2008, but yesterday news emerged from the Daily Utah Chronicle concerning a new model, the XOS 2, that can, "carry more weight and uses 50 percent less energy than its predecessor."

It was also revealed that Sarcos is currently developing two versions of the XOS 2:
The military version only has legs and was designed to help soldiers carry heavy packs. With XOS 2, soldiers would be able to carry the packs longer and have a decreased risk of orthopedic injuries associated with carrying heavy loads, Smith said.

The logistics version of XOS 2 has both arms and legs. The goal with this version was to design an exoskeleton that could help people unload objects off of trucks. Additionally, researchers wanted to reduce the risk of injuries, with the logistic version, they are also looking to decrease the amount of people it takes to complete these tasks by a third.
One of the enduring aspects of Iron Man's popularity is that anyone could potentially pilot his suit of armor (even if they didn't have the mind to build it). Although it's not likely to hit the battlefield anytime soon, the XOS exoskeleton, and its likely spin-offs, might allow Jim Rhodes types an opportunity to be peaceful War Machines.