Ubuntu 8.04; TightVNC

TightVNC, able to communicate with RealVNC. It also can remote desktop on Windows base system from Linux Ubuntu (*only tried on WinXP).

TightVNC installation
sudo apt-get install tightvncserver
sudo apt-get install xtightvncviewer

Run TightVNC viewer
at Terminal enter vncviewer, example:
user@computername:~$ vncviewer

small pop-out screen, enter ip addss and passwd

done