Welcome to another Mac user! After you do what is needed to find Classic on your system (I suspect that the restart with option key held down will be a solid clue), you will have a choice. If you do not have Classic or OS9 on any of your CDs I'd recommend going to Poser 5 (it will probably be cheaper), but if you have Poser 4 in hand and are used to using it on the PC, you may want to just stay with what you know for know. Most of the other apps are now written for OSX and why confuse the computer with 2 operating systems? Also check out the Apple website. There may be a downloadable version of classic which is part of the OSX you bought. After you have access to a Classic or OS9 environment, you can install Poser 4. Be sure to load all the stuff from the content CD because you do get extra figures and the templates. The next place to go is MartinC's soft-rabbit website. Get MacConverter and MacInstaller. (The links ought to be listed under utilities here.) Every time I unstuff or unzip a file I drop the folder on his appllets. We actually have life easier than the PC people! In the libraries of Poser 4 you can name them and organize them however you wish: by maker, by type of item, by figure it is for... then when using MacInstaller, you can tell it to put the files into the folder your have named. For example, I have a separate folder for Dragons and ALL dragons go there, no matter if they are by DAZ or PhilC or Sixus1 or Valendar... if I want to load a dragon I don't want to search all over creation for it! Let's see, you should also get Aladdin's "Stuffit" tools. I bought the Deluxe version a few years back because it was so handy and covered so many file types. You will discover that some tress at big-i and some models from the Japanese sites are compressed in strange formats... and Stuffit manages to unstuff them. On the Aladdin website, you can download a free version which will unzip and unstuff files. Once you have Poser up and running and your files where you want them, you shouldn't notice that much difference between the Mac and PC version. The hardest thing for me to learn about Macs was that to eject a disk you drop it in the trashcan... I was scared that the data would be lost, and I didn't own that disk (it was at work about a decade ago and seems silly now). HTH, Carolly