The market for educational software for Mac OSX is in a bit of a sorry state. Mac moms still need to hunt and dig to find learning and playtime software for their teenagers, elementary and pre-school children. So many learning titles were written years ago and far too many require 'Classic' Mac OS9 which the newer Intel Macs simply cannot run.
For any given publisher - at best only a few select titles in their library may be for Mac OSX. And even those publishers are hard-pressed to keep their Mac compatible learning software current with Apple's updates to the current Snow Leopard 10.6