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Virtual Network Computing (VNC) allows 2 or more users to share the same desktop remotely. As VNC is an IP based protocol, so you can use VNC to control local computers (e.g. office LAN) or remote computers (e.g. office working from home). All of the current major Linux distributions contain VNC software, although not all of them have it installed by default, so you may have to add the software from the
There are many VNC software packages, all of them having their own merits. Some of the more popular packages are RealVNC, and TightVNC. In addition to being distance independent, remote desktoping is platform independent meaning that Linux computers can work on a MAC, and vice-versa (as long as the software is correctly installed!).
VNC server/client data is by default sent unencrypted over the web, and so it is vitally important that you use a secure wrapper, such as SSH whenever possible.