Hallo Northern Sky planetarium program
Virtual Planetarium and other Astronomical Calculation Routines
Astronomical Ephemeris
Satellite tracking software
A free, fast and accurate routine to compute the position of the Sun
BoPlanets shows planets relatively to an observing planet.
A Re-implementation of Newcomb's Theory of the Sun
Sudden ionospheric distubance (SID) monitor
Sight Reduction for Air Navigation with Python
Inverse Compton emission from heliospheres of sun and stars
A C library of published theories of motion of solar system objects.
Astronomy Observation Planning Software