Xen -> Run Many Operating System in One System

Xen is an open source virtual machine monitor for x86-compatible computers. Xen makes it possible for multiple guest operating systems to run on a single computer by using a software layer called a hypervisor to mediate access to the real hardware. The hypervisor acts like like a traffic cop, directing hardware access and coordinating requests from the guest operating systems.


Originally, a guest OS would require modification to cooperate with Xen's hypervisor. This approach to virtualization was called paravirtualization. However, Intel and AMD have released a new generation of chips specifically geared towards virtualization. Intel calls their chip technology VT (Virtualization Technology) and AMD calls theirs AVT (AMD Virtualization Technology). A variation of Xen's hypervisor called HVM (Hardware Virtual Machine) is capable of working with the VT and AVT features in the Intel and AMD processors so that hardware calls from unmodified operating systems can be redirected


Xen is released under the GNU General Public License.



-Ganesh A.M