pscal is a simple shell script that creates PostScript calendars. It's not the most advanced calendar creator available, but for quick, nice looking calendars, it's very handy to have sitting in your bin directory. Features include: font selection, user-defined holidays, phase of moon, and days past/remaining in the year.
Asymptopia Flashcard System uses Motif and LaTeX to produce, manage, and use attractively formatted flashcards. You load some or all of your "collections" and set the timer for pop-up frequency. The GUI interface and "Collection Manager" make creating and modifying flashcards as simple as pushing a single button. A knowledge of LaTeX is only required when entering special symbols.
lin-seti is a command line program allowing the user to mantain a cache of work units for the Seti@Home client. It should run without any problem on Unix-like systems, including Linux. It is designed to be fully compatible with SETI Driver (similar software for Windows), so you can share the same cache on dual boot systems.
x10ephem computes sunrise and sunset times. It consists of a library and an assortment of utilities. The most useful utility is x10events, which parses crontab files and updates the time fields to track sun events. Combined with an X10 interface like HEYU or X10, this allows the scheduling of lighting events to follow the changing seasons and daylight savings time automatically. This application does not depend on X10; it can be used for any crontab entry you like.
Sunwait is a small program for calculating sunrise, sunset, civil twilight, nautical twilight, and astronomical twilight. It has options to wait until some time-offset from one of these events, making it useful for home automation tasks that should happen relative to the sun's position.
MultiSeti is a utility for the Seti@Home client which helps you manage multiple SETI packets. If you have dial-up access to the Net, want to download more than one packet, and don't want to run clients simultaneously, MultiSeti will run one after another (when one is finished analyzing, it starts seti to analyze the next packet).