The original AK-47 was one of the first true "assault rifles" to be manufactured, after the original Sturmgewehr 44. Even after six decades the model and its variants remain the most widely used and popular assault rifles in the world because of their durability, low production cost, and ease of use. It has been manufactured in many countries and has seen service with armed forces as well as irregular forces worldwide. The AK-47 was the basis for developing many other types of individual and crew-served firearms. More AK-type rifles have been produced than all other assault rifles combined.