I'm running Panther (10.3.9) and have NeoOffice intalled and working. My only gripe is it takes longer to load the program than did MS Office, but I feel good to be rid of more silly Microsoft nonsense (despite Office working well for me, I wanted to escape the clutches of Micro$oft). I could have installed OpenOffice, but it requires X11 and NeoOffice (in short, just about identical. from the same people, same programs.) works for me and can use it's own format as well as the Office formats.