PuTTY is a free software SSH, Telnet, rlogin, and raw TCP client. It was originally available only for Windows, but is now also available on various Unix platforms, with work-in-progress ports to Classic Mac OS and Mac OS X. Other people have contributed unofficial ports to other platforms, such as Symbian powered mobile phones. It is beta software written and maintained primarily by Simon Tatham, and is open source, licensed under the MIT License.
- The storing of hosts and preferences for later use.
- Control over the SSH encryption key and protocol version.
- Command-line SCP and SFTP clients, called pscp and psftp respectively.
- Control over port forwarding with SSH, including built-in handling of X11 forwarding.
- Full xterm, VT102, and ECMA-48 terminal emulation.
- IPv6 support.
- Support 3DES, AES, Arcfour, Blowfish, DES.
- Public-key authentication support.