[commercial - Win95/98/NT] Thirty full-screen Hubble photos for use as wallpaper and screen saver.
[open source - Linux/Unix] Interactive program for computing synthetic lightcurves and generating animated views and best-fit models of eclipsing binary stars.
[commercial - Linux] The new release of Linux for Astronomy includes over 3Gb of Astronomical software precompiled for the Linux (x86) operating system. Applications include a wealth of general purpose image and signal processing tools, as well as the state-of-the-art algorithms in use at observatories and universities worldwide. Facilities for processing the data products of the major space-based instruments (Hubble Space Telescope, EUV, Einstein, ROSAT, and IUE) are also included.
Astronomical software on Linux.
A large indexed collection of pointers to Linux applications.
[commercial, demo available -- Win95/98/NT] Includes calendars required by historians of astronomy and general historians. Many details are provided for Indian and Jewish calendars and much besides. There is also a display of positions of the Sun, Moon and planets, effectively replacing Tuckerman's tables. A horoscope display, and details of lunar visibility, are calculated from modern parameters.
A stellar evolution simulator designed for astronomy education.
Ksetiwatch monitors multiple SETI@home clients and automatically logs and manages completed work units.
Freeware allowing one to draw charts according to the data of 15 catalogs of stars and nebulae, as well as the position of planets, asteroids, and comets. Available in English and is translated in 8 other languages.
[commercial - Windows] Observation planning software for astronomers. Includes telescope control, logging, and charting.