I assume you're aware that that you're responding to a very old thread and that the DVD package has been available for many years. Can't imagine there is any issue of Mac compatibility (it's not software, it's DVDs), but you can probably ask Big Nick - there's an email link for him here: http://www.bignick.net/BoxLessons/Cajun_Accordion_Vol_2.htm
I would add that the package is very good - best of Big Nick's 3 volumes.
Thanks for the response. Have learned to be cautious, some sound files can be problematic. The real real question is accordion instructions or crawfish