There are a few of these "rich text box" controls out there.  None of them i've found work on safari.  I've done some searching and I've only found one answer that got close to giving an explanation as to why:  Read This

Is it true that because Safari is not a gecko based browser that it just doesn't have the mechanisms available to make something like Cute Editor fully functional in Safari? 

I don't see why Mac users should be shouting...they should be used to things not being compatible with safari. :P