Truth be told, I don't think there is any. The MacOSX build is nearly three years old, and AFAIK, was more of a curio (it was made just because) -- That said, I really can't say what features the MacOSX build has and hasn't got, since the main focus has been on the Windows build (and to a degree, *Nix). You should try to get a hold of Squall Leonhart over at EmuTalk, seeing how he's the one maintaing the "official" VBA-M site and ask him about it directly.