TightVNC

TightVNC is a free remote control software package.

With TightVNC, you can see the desktop of a remote machine and control it with your local mouse and keyboard, just like you would do it sitting in the front of that computer.

TightVNC is: free for both personal and commercial usage, with full source code available, useful in administration, tech support, education, and for many other purposes, cross-platform, available for Windows and Unix, with Java client included, compatible with standard VNC software, conforming to RFB protocol specifications.