Does Linux virtualization mean migration from Unix or Windows?

Does choosing to move applications onto virtual machines or creating a virtualized environment in general mean that I have to move chosen applications from Unix to Linux? Can we run Unix guests? Does every virtualization platform dictate that one would run their server-based environment on Windows or Linux?

Virtualization does not mean having to switch applications over to a given operating system. As virtualization software can run on Linux, Unix and Windows, so can all the applications that run within virtualized environments. All the major virtualization products from VMware, Citrix XenSource and Microsoft support a wide-range of guest operating systems which includes Linux, Unix and Windows. The one exception is OS virtualization products such as Parallels Virtuozzo and Solaris Containers. OS virtualization creates virtual environments (VEs) which can only be the same OS as their host.