Astrolog is a many featured and customizable astrology chart
calculation program for DOS, Windows, Mac, and Unix, used in 30+
countries on six continents.  It is 100% freeware and requires no
registration fee. :) The complete source code is available. Astrolog
features: wheels, aspects, midpoints, relationship charts, transits,
progressions, some interpretations, astro-graphy, local horizon,
constellations, planet orbits, dispositors, various influence charts,
biorhythms, different zodiacs, central planets, 14 house systems, 8400
year ephemeris, asteroids, Uranians, fixed stars, Arabic parts, script
files and macros, interactive PC & MS/X11 Windows graphics, smooth
animation of charts, graphic files in PostScript, Windows metafile,
and bitmap formats, and more!

Homepage:
https://www.astrolog.org/
