Virtuozzo is a propietary software product for OS virtualization developed by SWsoft, inc.
Virtuozzo creates multiple virtual independent environments (VEs, also known as virtual private servers, or VPSs) on only one physical server. This allows the sharing of hardware, time and effort in the system distribution and, sometimes, even the software licences between the multiple virtual environments.
One version that supports Linux has been available since 2001, and the version that supports Windows has been available since 2005.