1) Logic Pro 7.2.3 running on OSX Tiger 10.4.3 or higher for PPC Mac or Tiger 10.4.4 Intel Mac
2) The XSKey will run everything from Logic 4.8 to 7.2.3 but for version 4.8 (OS9 Only) you will need to make sure you have the special XSKey driver installed.
3) Logic Pro 8 & 9 use just a Serial Number
4) Logic Pro X use Mac App store receipt
5) Buy the White Apple XSKeys as they have all Emagic Products authorized
the older Emagic blue version of the XSKey are a cap shoot, who knows what you will get since the owner had to buy all the additional products separately