Useful for dispatching operating systems that do not use X. It is possible with Xen to start a VNC server, by modifying the start file of each virtual machine. LTSP script launch an application (vncviewer) with specific settings (to avoid compression and, hence, the load on thin client), and it connects to the particular machine. One must act on lts.conf in order to launch a script, that is similar to rdesktop, but it is adapted to VNC.