Can I run Zen Cart on an Apple Mac?

Yes, you can. To run Zen Cart you need an Apache server, PHP and a suitable database (ideally MySQL). OS X already ships with Apache, but if you are running Mac OS X 10.4 (Intel) or higher you may find it easier to simply install MAMP or the XAMPP package for MAC OS X. There is also help available from other Mac users in the support forum.