Sky Charts – Free program that enables you to draw sky charts according to the data of 15 catalogs of stars and nebulae, as well as plot the positions of planets, asteroids and comets.
Solar Kingdom – A real-time, photo realistic, 3D solar system simulator for the Windows based PC.
AstroCalculator – A Windows-based calculator program for general time and astronomical calculations, conversions and much more.
Astro Viewer – The Astro Viewer planetarium software displays an interactive sky map for any time and any location on Earth. A print function and a 3D solar system map are available as well.
Deep Sky Database – An online observing list generator for amateur astronomers who love to pursue deep sky objects.
Orbitron – A satellite tracking system that shows the positions of satellites at any given moment (in real or simulated time).
Universal Calendar – A nice free program that displays Moon phases, sunrise times and Easter dates. The source code is also available for download.
XEphem – Astronomical planetarium that tracks Earth satellites, controls LX200 scopes, analyses FITS images, and much more.
Moon Phases – View information and interesting facts about the Moon. Contains a full Moon calendar for the dates from 1940 to 2010.