VNC (Virtual Network Computing) is a graphical system designed for  desktop sharing.  It is much like the popular Windows program Remote Desktop.  VNC uses the RFB protocol to remotely control another computer. It transmits the keyboard and mouse events from one computer to another, relaying the graphical screen updates back in the other direction, over a network.

As VNC is platform-independent, it works well for cross-platform or linux to Linux connectivity.  Yes, a VNC viewer (client) running on any operating system can typically connect to a VNC server on any other operating system. There are clients and servers for almost all GUI operating systems and for Java. Multiple clients may connect to a VNC server at the same time. Popular uses for this technology include remote technical support and accessing files on one\'s work computer from one\'s home computer.
 VNC was originally developed at AT&T. The original VNC source code and many modern derivatives are open source under GPL (the GNU General Public License).

VNC SOFTWARE:

Real VNC
TightVNC
UltraVNC
Chicken of the VNC (Apple Mac OSX)