rxvt-unicode is a clone of the well known terminal emulator rxvt, modified to store text in Unicode and to use locale-correct input and output. It also supports mixing multiple fonts at the same time, including Xft fonts, real transparency, and an optional embedded Perl interpreter that allows you to extend your terminal easily.
KildClient is a MUD client written with the GTK+ windowing toolkit. It supports many common features of other clients, such as triggers, gags, aliases, macros, timers, and much more. But its main feature is the built-in Perl interpreter. At any moment, the user can execute Perl statements and functions to do things much more powerful than simply sending text the the MUD. Perl statements can also be run, for example, as the action of a trigger, allowing you to do complex things.
NOTE is a small console program that allows you to manage notes similar to programs like "knotes" from the command line. It supports different database backends for storage, and includes a DBI-based MySQL module and another module that uses a binary file for storage and a DBM module.
The mgetty package contains an intelligent getty for allowing logins over a serial line (such as through a modem) and receiving incoming faxes. The companion program sendfax is used for sending faxes from the commandline or from other applications. The third main component is vgetty/vm which can be used with a voice-capable modem to implement an answering machine, a voice menu system, and similar things.
Mail2sh makes it possible to carry out shell commands by email. Email is sent to a particular user on your host and the commands will be carried out if the user and password given matches ones in /etc/passwd. Commands are executed with the user's privileges, and combined with a PGP module ensures a certain level of security for use. Note that the system is not natively encrypted, so use of an encryption mechanism is highly recommended for security reasons.
GNU Teseq is a tool for analyzing files that contain control characters and terminal control sequences. It is intended to be useful for diagnosing terminal emulators and programs that make heavy use of terminal features (such as those based on the Curses library). It is primarily targeted at individuals who possess a basic understanding of terminal control sequences, especially CSI sequences. However, by default Teseq will try to identify and describe the sequences that it encounters and the behavior they might produce in a terminal.