Secure Back Door (SBD) is a tool that provides ultra-secure and minimal access to a computer, which allows you to run a single command based on a one time key. It is good if you don't want to have an SSH server running all the time, and only want to start it when needed. Because it is written in only a few lines of code, it is hoped that it will be less susceptible to security exploits than a program like SSH.
SecureCRT provides terminal emulation with secure remote access, file transfer (SFTP and X/Y/Zmodem), and data tunneling. Supported access protocols are SSH 1 and 2, telnet, telnet/SSL, and serial. It has emulation support for VT100/102/220, ANSI, SCO ANSI, Wyse 50/60, Xterm, and Linux consoles. It provides session management and tabbed sessions in one or more windows. The program is fully scriptable via VBScript, JScript, PerlScript, or Python.
Soiled is a Flash-based telnet client and terminal emulator, supporting both char-by-char and line-by-line mode. In line-by-line mode, it has some features that make it suitable for MUDs, such as aliases, macros, and hotkeys. Since it is implemented in Flash, it can be used from a Web browser.
Spinner is useful for keeping telnet and ssh links from dropping due to inactivity. Many firewalls and some ISPs drop connections when they are perceived as idle. By having spinner running, the server is constantly sent a tiny amount of data over the link, preserving the connection. Spinner thus acts as a keep-alive. It displays a little "spinning" ASCII character in the top left corner of your terminal. It supports any terminal capable of handling VT100-style escape codes. Spinner can also function transparently by only sending null characters to the terminal. In this mode Spinner supports any terminal. It also has a mode called "Ghost in the Machine" in which you can use Spinner to write the spinner character to any TTY, not just your own.
Terminal Mixer allows sharing the stdin/out/err of a process through a Unix socket, TCP, or raw ethernet (the latter only on Linux). It allows sharing a pseudo-terminal as well, for terminal-aware applications. The users can be allowed only to watch, or even to contribute. You can run your favourite 'vim' or 'bash' and access it remotely, even with multiple users using them.