PuTTY is a free SSH client.

AeroAdmin is a zero configuration free remote desktop software. Use it for quick and easy remote desktop access and PC control.

ASG-Remote Desktop integrates a large variety of connection protocols, allowing you to manage Windows, Citrix, Linux/UNIX- and Macintosh systems remotely.

LogMeIn is a remote desktop management and remote administration solution.

dualmon is a free remote desktop and remote support software.