QEMU is a FAST! processor emulator using dynamic translation to achieve good
emulation speed.
QEMU has two operating modes:

    * Full system emulation. In this mode, QEMU emulates a full system (for
    example a PC), including a processor and various peripherials. It can be
    used to launch different Operating Systems without rebooting the PC or to
    debug system code.
    * User mode emulation (Linux host only). In this mode, QEMU can launch Linux
    processes compiled for one CPU on another CPU. It can be used to launch the
    Wine Windows API emulator or to ease cross-compilation and cross-debugging.

As QEMU requires no host kernel patches to run, it is very safe and easy to use.

WWW: http://wiki.qemu.org/Main_Page
