PAC provides a GUI to configure SSH and Telnet connections, including usernames, passwords, EXPECT regular expressions, and macros. It is similar in function to SecureCRT or Putty. It is intended for people who connect to many servers through SSH. It can automate logins and command executions.
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.
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.
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.
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.
vmodemd is a telnet server designed to run old DOS BBS systems and door games. It listens for incoming TCP connections on a defined port, does a minimal telnet handshake if needed, and then starts to proxy all data to a PTY which is bound to a dosemu virtual serial port. vmodemd supports any number of virtual modems, can display customized banners if all modems are busy, can terminate a serial app when a telnet connection is unexpectedly dropped, and run custom scripts before passing control to dosemu, allowing you to pass relevant data like incoming IP address to the DOS app.