We consider the first stable and mature version of Mac OS X to be 10.2 - some of our older titles will indeed run on Mac OS X from 10.2.8, however as time passes, supporting applications such as Internet browsers and related plug-ins are retired. As such, new titles will progressively require later versions of third-party applications - this restricts our ability to develop and release our software for the older versions of OS X. OS9 and Classic is not supported in any form.
Our current support extends from OS X 10.4.11 and later, though original developments were constructed to operate successfully on OS X 10.3.9 (10.3 originally released in 2003) we can no longer effectively support earlier Mac OS than 10.4.11.
It is important that you maintain security and other system software updates as they are released by Apple. OS X users should ensure that they upgrade to the most recent version to enjoy the benefits of improved security and stability. These upgrades (e.g. 10.4 to 10.4.11) are typically available at no cost through the Apple website.