PuTTY is a terminal emulator application which can act as a client for the SSH, Telnet, rlogin, and raw TCP computing protocols. The name “PuTTY” has no definitive meaning.
PuTTY was originally written for Microsoft Windows, but it has been ported to various other operating systems. Official ports are available for some Unix-like platforms, with work-in-progress ports to Classic Mac OS and Mac OS X, and unofficial ports have been contributed to platforms such as Symbian powered mobile phones.
PuTTY was written and maintained primarily by Simon Tatham and is currently beta software. Licensed under the MIT License, PuTTY is free and open source software.