Linux supported virtualization since many years ago. One of the first implementations was User-mode Linux, that
appeared as patch to the 2.2 series Linux kernel.
Today there are several mature and powerful virtualization technologies, for Linux and commercial Unixes as well.
- The XEN HypervisorRuns on X86 and AMD64 processors, tipically used to virtualize Linux servers, other OSs are also supported. Open Source.
- OpenVZ For Linux, is an OS-level container-based, as Usermode Linux, BSD Jails or Solaris zones. Open Source (GPLv2)
- IBM PowerVM Runs on IBM POWER architecture. Mostly used for AIX but supports PPC Linux and i/OS (formerly OS/400) as well.