Software

For web-based free astrology calculations on any computer system with internet access, go to:

http://www.astro.com/horoscopes

This is actually the Astrodienst.com website. Click on Extended Chart Selection, near the bottom of the page, 2nd column.

To get the midpoints, click on:       Pullen/Astrolog
Then choose from the pop-up menu:  Aspect/midpoint grid chart


Another easy free web-based astrology site is http://www.alabe.com

Some other great free websites:
http://www.astro.com/swisseph/swetest.htm
http://www.true-node.com/pos/
http://ssd.jpl.nasa.gov/horizons.cgi
http://www.zodiacal.com/chart.htm
http://www.true-node.com/eph1/
Free Astrology Calculators

Free Ephemeris text files:
http://www.zodiacal.com/ephemerides/index.php

A great free astrology program aimed at Windows users:
http://www.astrolog.org

... by Walter Pullen. Some of this program is actually used by Astrodienst in their free astrology zone.

Runs on Windows and Mac. The Mac version is for non-intel chips only (G4, G5, etc) and is only run as a command line tool. It's not the most user friendly program and takes a little time to get used to, but is very accurate and has lots and lots of features.

see also:    
http://www.expreso.co.cr/centaurs/riyal.html
http://www.zodiacal.com/resource/sharewre.htm
 
For reviews of many other astrology programs for sale see:
http://soulhealing.com/softwarereviews.htm

TimePassages 5 for the Mac has a beginner's version which is $49.95 and is great software for the Mac in that price range:
http://www.astrograph.com/astrology-software/basic.php

Great list of astrology app for iPhone (but not necessarily free):
http://www.astrologythoughts.com/astrology-iphone-applications/ 

Here's a collections of free, open-source astrology software:
http://sourceforge.net/directory/os:mac/freshness:recently-updated/?q=astrology

* This article started as a follow-up to a discussion about astrology software we had in class at Carroll Righter's.