openVZ virtualization technology offers you the best of a shared kernel and no reboots to change/upgrade resources!

Xen virtualization technology provides you with absolutely non oversold VPS's and dedicated kernels, the downside is that it requires a reboot after upgrading resources etc.

Xen HVM-ISO virtualization technology provides you with everything you need - You can run Windows/Linux or any other OS, just give us the ISO and we will place it for you if we do not support it already. On Xen HVM-ISO, we provide Windows 2003 Server and Windows 7 aswell as CentOS. Control your server via virtual keyboard video mouse (vKVM) and even setup the installation of the ISO if you need!