Clairvision Astrology
http://astrology.clairvision.org
(It's the replacement for Canopus)
There is a free online astrology software called Clairvision Virtual Astrologer.
It really has almost everything you'd want from an astrology program, and it's all online, for free. It's amazing that this is free.
There's also a course that covers some basic stuff, like what's what in a chart, and some not so basic, like understanding the solar system and the way the planets actually move. I really like this because they make a point of connecting astrology to astronomy. Anyway, the site says more lessons are coming so I guess I'll be back.