Another one is Deepsky Astronomy Software.
Rod's the king, I found these articles quiet helpful for information on the following
Skytools
http://skywatch.brainiac.com/sw1203.pdf
Astroplanner
http://skywatch.brainiac.com/swfall06.pdf
Deepsky
Part1
http://skywatch.brainiac.com/swsummer05.pdf
Part2
http://skywatch.brainiac.com/swfall05.pdf
Regards
Fahim