yup, pretty much The best part about IBM mainframes was/is that you shouldn't need to worry about copying the OS to keep the App happy. The mainframe OS effec

yup, pretty much The best part about IBM mainframes was/is that you shouldn't need to worry about copying the OS to keep the App happy. The mainframe OS effectively provides a VM in a similar style to python or java. You tell it what version of machine its supposed to run on and it'll provide an environment with all the quirks. The article goes on to talk about uOS type systems, which are there to provide a Linuxy shim (with all the quirks) between the hypervisor and the App. (do you start to see where I'm going? :) )