Based on the can it/not attach to the current desktop we have 2 categories:

1. this works by using a wrapper script for Xvnc, the free X server for VNC (Virtual Network Computing). It provides all capabilities of a standard X server, but does not connect to a display for itself. Instead, Xvnc creates a virtual desktop you can view or control remotely using a VNC viewer.
   • Real VNC
   • Tight VNC
2. attach to the current desktop or another one available. Works the pretty much the same way as the regular VNC server with some extra options available.
   • x11vnc.

Start up with the following command:

$x11vnc -display :0 

To scale the display to a different size, smaller:

$x11vnc -scale 2/3 -display :0 

If you don't have direct access to the other machine you will have to either use:

• ssh port forwarding

  $ssl -L 5900:host_vnc:5900 user@host_firewall 

• VPN - Virtual Private Network

Example of usage for a SSH forwarded connection to the local machine:

$vncviewer -truecolor -encodings "copyrect tight zrle hextile" localhost:0