Putty, Simon Tathams quietly developed SSH client, has become one of my most often used tools over the past several months, particularly during eWeek Labs ongoing Openhack III security test. Secure Shell, a secure, remote-terminal protocol, is a basic tool for administering secure Unix-based systems, and I use it instead of Telnet whenever I can.
Putty is simplicity itself to use. Theres no install—just download the executable and run it—and it uses the X Window standard, left- and right-button, cut-and-paste commands that work so well in command-line environments.
In addition, Putty gained RSA public-key authentication in the fall, the one feature that had kept me using SSH Communications Securitys Secure Shell. Using keys is a better approach than using passwords because keys cant be guessed and provide a measure of physical security (you must have the key file on your system to log in).
Putty, pscp secure file transfer and key management tools are free for download and use (including commercial use), and the source code is available. The Windows-based software can be found at www.chiark.greenend.org.uk/~sgtatham/putty.