Here is discussion of programs which run on Linux for use in finding objects,
natural and man-made, in the sky.
XEphem has been the pet project of one of us (Downey) for the past 15-odd years. It has grown to become one of the more capable interactive tools for the computation of astronomical ephemerides.
XSky is by Terry R. Friedrichsen, email@example.com. XSky is essentially an interactive sky atlas.
Skymap is an astronomical mapping program written in Fortran and C for unix workstations by Doug Mink of the Smithsonian Astrophysical Observatory Telescope Data Center.
Xplns reproduces real starry sky on your display of X Window System.
Nightfall is an astronomy application for fun, education, and science. It can produce animated views of eclipsing binary stars, calculate synthetic lightcurves and radial velocity curves, and eventually determine the best-fit model for a given set of observational data of an eclipsing binary star system.
NOVA free Integrated
Observational Environment for astronomers.
Every list needs a miscellaneous section, and this is it for Software.
IRAF is a gigantic but exceptionally capable astronomical analysis system, shepherded over the past 20-odd years by Doug Tody of NOAO. It has accumulated innumerable authoritative contributions from leading astronomers in all areas of astronomical data analysis. If you have a serious interest in astronomical data reduction and significant time to invest, this system will reward you mightily.