I'm referring to the open Hotspot which almost everyone uses, not some specialized JVM products which are closed-source. You do bring up an interesting point th

I'm referring to the open Hotspot which almost everyone uses, not some specialized JVM products which are closed-source. You do bring up an interesting point though. As for the type of hypervisors you're referring to, those things are effectively half-baked operating systems. That's why something like KVM is better -- you're not pretending to be a non-OS while slowly reinventing a wheel that the *nixes have and always will do better. I think we're beginning to wander massively afield though! :)