On my machine, Windows 10 is a virtual machine running under VirtualBox which is running under OS X “El Capitan”! So, we have a system as in the above diagram. That’s how robust VirtualBox is. Yes, I know other VM solutions can do this, but are they free?
I’ve become a big fan of Oracle VirtualBox particularly on OS X. Its low overhead and openness and, as I noted at the beginning, its robustness and versatility, make it a great platform for both test and production systems. Oracle VirtualBox gets a Gearhead rating of 5 out of 5.