libAstronomy provides a set of astronomical routines to ease the calculation of ephemerides. It includes mathematical functions to compensate various astronomical phenomena like precession, nutation, etc. The getconstellation routine finds the constellation for a given coordinate. It also calculates the positions of the sun and moon in two different precise ways.
libnova is a general purpose, double precision, celestial mechanics and astronomical calculation library. It can calculate aberration, nutation, apparent position, dynamical time, Julian day, precession, proper motion, sidereal time, solar coordinates (using VSOP87), coordinate transformations, planetary positions (Mercury - Neptune using VSOP87), planetary magnitude, illuminated disk and phase angle, lunar position (using ELP82), phase angle, elliptic motion of bodies (Asteroid + Comet positional and orbit data), asteroid + comet magnitudes, parabolic motion of bodies (comet positional data), orbit velocities and lengths, atmospheric refraction, rise/set/transit times, and semidiameters of the Sun, Moon, planets, and asteroids.
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.
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.