I haven't really checked as I prefer to read on iPads or Kindles rather than my desktop computer or MacBook Pro 15 Retina. But I have never seen much available for Mac OS X or even Windows in eBook readers. I guess the market is too small for those platforms. Even in the iOS/Android OSes most of the reader apps like iBooks and Kindle have very limited book format settings. You generally have to get a 3rd party reader app like Marvin to have the ability to set book formatting to your preference. I'm not sure why there are so few options and most have very limited format settings, but that is the not so little, dirty secret of reader apps.