AstroWin has tons of calculations such as progressions, transits, solar and lunar returns, astro-locality, and much more. Several programs contain source code so you may develop your own astrology programs.

Astrolog 5.40 is a 100% freeware astrology program, with versions for Windows, DOS, the Macintosh, and Unix, and the complete source code is available too

Configuration Hunter is a free astrology software and it was designed with the purpose of helping you in your astrological activities and it was built on the Swiss Ephemeris (www.astrodienst.com). It is not created to replace any other astrology software that you are working with but to extend their existing functionalities.

Freeware program for the traditional Four Pillars Chinese astrology (Ba Zi)

The Mayan Horoscope is one of the most sophisticated inventions of an ancient Mesoamerican culture steeped in astrology and magic. The centerpiece of this system is a 260-day sacred “year” known as the Chol Qij, or count of days.

What Watch is a powerful tool that covers many areas and techniques of astrology. Its purpose is to get quick access to relevant information and displaying it in a concise and no-nonsense way: Keep it simple while providing all that is necessary.

ZET is a powerful astrology program for the professional astrologer, an effective resource for astronomy students, and a wonderful training tool for beginners. ZET combines both astronomical and astrological functions, with lots of astronomical data and graphical information.