What is QEMU?

QEMU is a generic and open source machine emulator and virtualizer. When used as a machine emulator, QEMU can run operating systems 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 reasonable speed. When used as a virtualizer, QEMU achieves near native performance by executing the guest code directly on the host CPU. QEMU supports virtualization when executing under the Xen hypervisor or using the KVM kernel module in Linux.