What browsers are we talking about in the MAC's? As far as I'm concerned, this menu system is more than only JavaScript. It also contains DHTML which is the same as "don't use this" in my humble oppinion.

Sorry for being unspecific here, but I have encountered better menu systems than this, however I do not remember the name of it but they hade a specific chart on their website containing compability both with browser versions and operating systems.

I would recommend you to not use menu systems like these due to cross browser incompability issues. It can look good and at the same time work smoothly with gif's and minor javascript coding, when creating menus.