XTRON Laboratories is a Megacorp specializing in military equipment. Their two most famous products are the Mark 100 "Centurion" Power Armor suit, the original Nanotech Armor suit, and the AT-14 Skyranger Assault Pinnace.
Behind the Scenes
Nathan Bax named the corporation in his original description for the nanotech armor. Martin noted the similarity to the game XCOM, and used them as the company who built the AT-14 due to it being a blatant ripoff of the assault transport in that game.