You'll have a hard time listing "all" astro software, as little utilities are written all the time.
Extremely comprehensive list here:
http://www.pierpaoloricci.it/downloa...ftware_eng.htm
Do a search in this forum for some handy free apps written by sheeny. I'm sure others have contributed here too, but Al's leap to mind first for me.
I made a list
here a while ago of software I have used.