Planetarium Software?

On the off chance that someone following this blog has an answer for this, I'm looking for planetarium software for an online class I am developing for Fall 2008.

Minimum Qualifications

1. Cheap, or free with a good textbook


2. Works on Windows XP and Mac OSX.4


3. Ground can turn on and off


4. RA/Dec coordinates


5. Alt/Az coordinates


6. Sun and all planets


7. Messier objects


8. Ecliptic line


9. Effectively infinite time in the past and future


10. Asterisms ("constellation" connect-the-dots drawings)


11. Constellation borders (outlines)


12. I can learn it with a user's manual and/or FAQs


13. Students can learn simple tasks with hand-holding

Preferred Qualifications

1. Free


2. Works on Vista and all other platforms


3. NGC and other deep-sky objects


4. Images of objects


5. Ability to move forward in 1-day increments without showing intervening time, so as to demonstrate
   
   1. the analemma,
      
   2. which constellation the Sun is in throughout the year,
      
   3. which constellations are visible at night throughout the year,
      
   4. the motion of the planets relative to the Sun, and
      
   5. the motion of planets relative to the sky.
   
   
6. Ability to move forward in other time increments, such as a year


7. Precession


8. Ability to lock on an object (such as the Sun or Moon) while progressing time


9. Easy to learn

FWIW, Google Sky fails Minimum #9, Starry Night Pro 3.1 passes Minimum #1b but fails Minimum #2 and may fail others since I can't run it to find out, Starry Night Pro 6.2 fails Minimum 1, I suspect The Sky 6 fails Minimum 1 but I haven't done enough research to be sure, and Stellarium appears to fail Preferred 6. Some combination of Stellarium and Google Sky appears to be what I'm going to have to deal with at this point.

X-posted a few places