Born of the minds of Gordon Ingram and Mitchell WerBell III, the Military Armaments Corporation’s Model 10 submachine gun is a landmark development in the history firearms. Developed in the late 60's (a time where rifles were seen as the end all be all for defense and offense), the MAC-10 and its many variants re-popularized the submachine gun, which would later find use in special forces operations and military trials. Ingram and WerBell hoped the MAC might have a role in Vietnam.
Interestingly, the MP5 was designed around the same time as the MAC-10, and we can see the different ideas they represent. The MP5 is an elegant, expensive police weapon, and the MAC-10 is a cheaper lead spitter that gained notoriety (even directly named in the 1994 AWB) as a weapon for drug runners and gang members. Take a look at any 80's action movie, and the criminal element will usually have an AK or a suppressed MAC.
The MAC-10 was designed around an open bolt blowback mechanism, often coupled with a two-stage suppressor designed by WerBell himself. This bulky design enables the MAC-10 to boast its sheer fire rate, which can approach 1300RPM or higher, depending on whether it's chambered in .45ACP or 9x19mm. The suppressor is of special note, with the Military Armaments Corporation making a point to advertise its two-stage suppressor as a part of the deal.
The MAC-10 is the predecessor of two variant lines: the MAC-11A1 and the MAC-11/9. The two are similar. The MAC-11A1 is chambered in .380ACP with a slightly longer and narrower receiver than the MAC-10, and the MAC-11/9 is chambered in 9x19mm with an even longer receiver. Both use the same suppressor, a modified version of the MAC-10 suppressor, which uses wipes instead of baffles.