QEMU is a generic and open source machine emulator and virtualizer.

When used as a machine emulator, QEMU can run OSes and programs made for 
one machine (e.g. an ARM board) on a different machine (e.g. your own PC). 
By using dynamic translation, it achieves very good performances.

When used as a virtualizer, QEMU achieves near native performances by 
executing the guest code directly on the host CPU. A host driver called 
the QEMU accelerator (also known as KQEMU) is needed in this case. The 
virtualizer mode requires that both the host and guest machine use x86 
compatible processors.

NOTE:
qemu builds man-pages at compile-time; to do so, /sbin must be in the
current $PATH.  Be sure to run the script as root ( "su -" ).

spice is an optional dependency.