GI_Joe simulates Global Illumination. If you don't know what that is, do some searching around the lighting/rendering forum. You'll also find more info on GI_joe there.
The script was developed for PC and to be honest, I don't know how Maya's directories are set up on Mac so I couldn't tell you what you'd have to do to convert it. I suppose conversion is possible, though. (In the script itself, you have to edit the script to reflect your maya directories).
Just curious: If you don't even know what it is, why are you so eager to get it? It's not like it's a cure-all that will make your scenes beautifully lit or anything. It has it's place of course, but a tendency of people new to maya, especially on the forums, is that they see a more advanced user using it, then think "If I use it, my scenes will just as good." That's not really the case. Take the time and learn the art of basic 3-point lighting first and build from there.
Just my .02
"Terminat Bora Diem, Terminal Auctor opus."
Last edited by NitroLiq; 13-05-2003 at 01:25 AM.