The Heckler & Koch MP5 is a 9mm submachine gun of German design, developed in the 1960s by a team of engineers from the German small arms manufacturer Heckler & Koch GmbH (H&K) The MP5 is currently one of the most widely used submachine guns in the world, having been adopted by numerous military, law enforcement, intelligence and security organisations. In the 1990s, Heckler & Koch developed the Heckler & Koch UMP, the MP5's successor, though both remain in production.