Originally developed as a freeware project within AT&T, VNC - short for virtual network computing - now has several freeware variants.
RealVNC (aka WinVNC) has continued to be developed by the former AT&T team, who make money by selling enterprise support services to company users.
You can download the software, which is also available in Linux (X86) and Solaris 2.5 variants, from the site, or get a CD-ROM with everything on it, including some interesting utilities, for $49.95.
Documentation is relatively thin and couched in tech-speak. This is definitely not a package for the novice user.
We found the software to be an absolute pig to set-up in Windows 98, although it is much easier in Windows XP.
Whilst the interface is intuitive most of the time, if it fails to connect, it can be a lengthy process to work out why the connection doesn't work. We've encountered scenarios where the best solution to a no-connect situation is simply to delete, reboot and reinstall the software.
There's no integrated encryption, which means that data flowing across the internet can be sniffed and viewed by just about anyone who knows your IP address.
The good news is that a second freeware package, Putty, can also be downloaded from the RealVNC site and run in parallel with the remote access package. It supports SSH and allows secure tunnels to be made across the internet or any TCP/IP-based network.
You can even configure Putty and RealVNC to route an encrypted tunnel back from the destination machine, allowing you to carry out commands on the distant machine without the remote user being aware of what's actually happening.
This is dangerous stuff, so you'd better make sure you have security rules in place within your organization before you actually use this package.
There are positive aspects of RealVNC, including the fact that software is just 700KB in size in its host/viewer combination. The viewer-only, meanwhile, is just 150KB - meaning that you can run the whole ensemble from a floopy disk. Try doing that with any of the competing packages in this space.