As far as I am aware now that Mac has gone Intel, there will be no reasons for any difference.
I think even prior to that the PC, MAC and Linux versions are all completely the same. Same file types and they can be opened by each version. IF I am wrong tell me, I have been reliably informed that they are all the same
Chris (formerly R@nSiD)
Twitter
When the power of love overcomes the love of power the world will truely know peace - Jimmy Hendrix
Winner SM VFX Challenge 1
3rd Place SM SteamPunk Challenge (May 2007)