If you need map software for the Mac OS, we suggest you use iMapBuilder Online, which is a cloud-based online mapping software system.
iMapBuilder Online let you create and edit maps directly insider your web browser, no installation required and you can instantly publish and share the maps you have created. Please signup a free trial a/c at:
The map editor works on both Mac OS and Windows. And YES -- with iMapBuilder, the maps you built on can be viewed by users of both Windows and Mac OS.