hexcompare is a curses-based utility to compare and identify differences between two binary files. These differences are then represented visually with an interactive block diagram. Hexcompare is useful in forensics cases when you have two files and you want to compare them to find out whether they are identicals or similars.

pyca is a set of Python scripts written Michael Ströder. They provide an almost fully fledged Certification Authority. Support for issueing email and authentication certificates works fine.

This program can be used to train people to spatial mechanics at an elementary level. You are given the power to launch a satellite, from outside the atmosphere, around a handful of predefined planets, or around any special object you may imagine. Input the initial velocity vector of the satellite, and you will get the simulated trajectory, as well as some information like the plots of variation of speed. As an extra, you can compute a movie, which represents the planet seen from the satellite's point of view during its orbital period.

The xwrited utility displays write(1) and wall(1) messages as desktop notifications. A notification daemon compliant to the freedesktop.org Desktop Notification Specification draft needs to be running in order to display the notifications.

An alternative standalone (doesn't use zwgc) Zephyr (instant messaging) client. Has perl hooks and a curses UI; supports Kerberos if libzephyr4-krb is present. (Also supports AIM.)