PuTTY is a volunteer developed, free, open source program for communication via protocols such as SSH and telnet.[1] It is designed for programmers and network administrators, and does not include documentation or in-depth descriptions. For this reason, inexperienced users may find this software confusing.[2] PuTTY was designed for the Microsoft Windows operating system, but has since been officially expanded to Unix-like systems and Mac OS Classic and Mac OS X. Unofficial versons have also been created for Symbian and Windows Mobile.[3]