Sun's FOSS VirtualBox hits the sweet spot for Linux (ITWire)

the only way to run an unmodified OS without chip support is with emulation. Qemu, virtualbox,
and vmware all support this mode of operation.

if you can take advantage of the support in recent chips for virtualization, you can do less
emulation and gain a significant speed advantage.

but to claim that virtualbox doesn't so emulation, doesn't require chip support, and can run
unmodified OSs is incorrect.