1. It looks like some people here have Mavericks running. I'm assuming that's a beta. Is there a date on when it will be released proper? 2. When I upgrade from my current 10.8.5 will I need to wipe my files off my hard drive. Or can I just upgrade the OS, and all my files and applications etc will be intact? 3. This question is less about the OS; more about iBooks: The reason I want to upgrade, is so I have iBooks on my laptop. I'm making a book, with iBooks Author, and I don't have an iPad to test it on. So as I understand, with the upgrade, I'll be able to test it... But with iBooks on my MacBook, will I be able to test how the book will appear on an iPhone, too? The file I upload as an iBook will that file serve the iPad and the iPhone?