Probably the most famous, non-American, belt-fed machine gun in history, it’s awesome rate of fire was 1200-1500 rounds per minute (that’s 20+ rounds per second!). Since its introduction in 1942, it has remained in front-line service with many nations, and is still being used in active combat today in a very slightly modified design (MG3).
It’s modern version, the MG3, is not radically different that its parent. Most of the parts are actually interchangeable. The biggest differences are the rate of fire was reduced slightly (to a mere 900 rpm), and the flash hider was simplified.
This makes the MG42 the longest serving light machine gun in the world!