Virtual Private Systems for FreeBSD (VPS) is a novel virtualization implementation which is based on the operating system level. Its main design advantage is the multiplexing rather than isolation of global resources, as e.g. "Jail" does. This permits the virtual environments being much more similar to the non-virtual ones, reducing configuration and adaption effort. Additionally it supports live migration which can largely reduce maintenance time and therefore sysadmin hours and service downtimes.