NOTE: Ableton Live 5 isn't available for Mac Os 9 (This is listed for Comparative Reference Only)

trying to find the "Whats new" documentation from 5 to see specifically but for now heres some articles that may give that info

later versions of ableton that came out featured in sos:
http://www.soundonsound.com/sos/nov05/articles/abletonlive5.htm
http://www.soundonsound.com/sos/nov06/articles/live6.htm 
http://www.soundonsound.com/sos/feb08/articles/live_7.htm
http://www.soundonsound.com/sos/jun09/articles/live8.htm