From Halopedia, the Halo wiki
Misriah Armory is a major weapons, armor, and vehicle manufacturer based on the planet Mars in the city of Shoreline. It supplies a significant portion of the weapons and matériel used by the United Nations Space Command, and is considered the largest military weapons and equipment manufacturer in human history.
Most of the UNSC's small arms and field equipment, as well as many terrestrial and aerospace vehicles, are produced by Misriah Armory. In addition to their own designs, Misriah manufactures technology created by other firms, most notably AMG Transport Dynamics' M12 Warthog. The company also sells combat-grade weapons (presumably demilitarized) on the civilian market. Products, at least on planet Reach, were distributed through the Department of Supply Distribution.
Misriah had facilities spread out over much of human occupied space. Some known facilities are:
Misriah Armory manufactures a significant portion of the weapons, emplacements, and vehicles used by the player in each Halo first-person shooter and both of the Halo Wars titles. Their logo, or name can be seen engraved or painted on several of them.
List of appearances