> Processes are pretty heavyweight as a way to perform this sort of isolation. How do you figure? Processes on some OS's, such as Linux, are pretty cheap. So w

> Processes are pretty heavyweight as a way to perform this sort of isolation. How do you figure? Processes on some OS's, such as Linux, are pretty cheap. So what are you considering heavy? And how do you imagine a "process switching in userspace" type thing to not just have the same weight as real processes? What's the expensive thing you're trying to eliminate?