to repeat John’s post to an extend, we no longer support Mac OS 10.4 indeed, a decision/move we spread across 2 full years at this stage. The last EZdrummer version tested on Mac OS 10.4 is about as old as that, version 1.2.1, and is no longer in print (though that does not mean you can’t find copies lying around).

That does not mean that newer versions won’t work, in fact we have made every effort when assembling those newer versions not to introduce any code/routines that we knew would create a compatibility issue, but it remains that we haven’t extensively tested those changes on Mac OS 10.4 (well, in fact NO testing was performed for the current version 1.3.1, and only the minimum resources was spent on this aspect when 1.3.0 was prepared for release).

It is very likely that there are no issues with version 1.3.0, which is the current full download, but I would strongly recommend, should your friend decide to buy EZdrummer, to not update past this version. And of course, while there is no immediate plan to do so, we reserve the right at any point to update this full installer to a newer version, that makes it incompatible with Mac OS 10.4, so I’d recommend backing it up (or buying a physical disc, which currently should be 1.3.0, or older) in case a reinstall is necessary at some point.

That said it’s unlikely that the full download will change in the near future, but we of course have to balance that decision with any support issue it might create for customers running more recent version of the Mac OS (or Windows OS for that matter, though there are no big concern on that front right now).

I hope this info allows your friend to decide whether to invest in EZdrummer for use on Mac OS 10.4.