The HK MP5 is simply the most successful and popular 9mm submachine gun ever invented. Despite being originally made in the 1960s, it is still popular with military and law enforcement units all around the world. Even in the face of newer HK submachine gun designs such as the MP7 or the UMP, the MP5 shows no signs of decreasing its popularity. The only other submachine guns that are as iconic as the MP5 are the Thompson .45 ACP. submachine gun and the Uzi 9mm.
As a submachine gun, the MP5 is not available in select fire mode to American civilians, but it is available in a semi-automatic only in the form of the HK SP5. In addition, there are many clones of the MP5 produced for the American market as well, including the Zenith ZR5S and the PTR-9CT.
The MP5 is currently in service with the militaries and/or law enforcement units of over 40 nations. It was and is widely issued with US SWAT teams, although its popularity has decreased a bit due to many such teams transitioning over to the AR-15 series off rifles, which offer greater stopping power due to firing rifle ammunition.