This is the old BSD tn3270 made to compile under Linux/GLIBC. It is not perfect and not being actively maintained. Also in the same directory is 3270v4.1 from CERN, made to compile under Linux/GLIBC, which looks nicer. If you are interested in these programs, you may also want to look at the Linux tn5250 project.
DataReel is a free, cross-platform database and communications toolkit. It can be used to rapidly develop and deploy multi-threaded database and communications applications. The DataReel toolkit is composed of a modular C++ library designed to build cross-platform infrastructures for end-user applications, embedded systems, and reusable libraries. DataReel's unique modular design simplifies adaptation, allowing you to determine the level of complexity. DataReel makes Internet connectivity and database programming easy.
PowerTerm InterConnect is a fast and secure terminal emulator, providing comprehensive emulation support via various communication modes. It meets the host access needs of many organizations, supporting the broadest and widest range of hosts, including IBM Mainframe, IBM AS/400, UNIX, OpenVMS, SCO, Tandem, HP, ANSI, Data General, Wyse, Televideo, and more. PowerTerm InterConnect offers state-of-the-art features, including SSH and SSL security, customizable function keys, multiple concurrent sessions, scripting, a menu bar, scalable and selectable fonts, intelligent copy and paste, printing, and more.
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.
blinkperl is a telnet server (written in Perl) which plays a random (ASCII-Art) Blinkenlights-Movie if a telnet client connects. In a properly configured system, you do not need a 'usual' telnet server (because of the plaintext password transmission, ssh is better and uses another port), so why not play ASCII-Art Movies on the telnet port?
Zuul was yet another PHP frontend for mldonkey. It has been out-of-sync with current mldonkey development for some time, however, and exists now only as a reference for the more current fork of the project, Web-GMUI. Zuul is unlikely to function properly against any available mldonkey releases, so file releases are unavailable at this time. CVS from sourceforge is still available, however.
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.