The central mainframe for all Macs. PC users must constantly attempt to pwn the mac mainframe in order to maintain their h4x0r status with their PC buddies. This is not so much something that exists but rather something most people would like to hack.
Also used as an expression of a like of something or victory
<Andrew> Hahah and then I went to download it and it turned out to be porn!
<Greg> OMG LOL THAT PWNS TEH MAC MAINFRAME.
<Sam> Instense mofos, that certainly does hack the mac mainframe per say.