Great software for creating/editing eBooks. Don't know if there's a better one for OS X out there… I've tested Sigil, not a chance. With iBA you can create ebooks in Apple's proprietary iBooks format, including InDesign IDML import, but also epub (v3), sadly not with InDesign import, and there's no in-app cross-transfer between iba-projects from epub to ibooks and vice versa. You would need to export your epub project as an .epub file, then re-import that into an iBA ibooks project for Apple-proprietary pimping. All in all it's very intuitive, for quick studies anyway. It's made to go smooth with Apple products and OSs, but if you don't go nuts on the formatting, your epubs will look good on your eInk reader, in Calibre etc. As a print author I usually work out of InDesign, but it's way too complicated to use it for eBook creation, if your work is heavy on special formatting, multiple fonts etc. Better just export an RTF, copy into iBA and boil it down into a clean, ascetic ebook. Very simple to do with this software. And it's free as well. I just hope my publisher will accept my .iba files. ;) PS: I haven't worked with the Apple ibooks templates, simply because epub is the way to go. But the functionality seems to be pretty great. So if you're not bound to the regular epub/azw market, go with the ibooks format. A lot of possibilities there.