EPUB 3 Support
iBooks 3.0 supports EPUB 3 for both flowing and fixed-layout books including features such as pop-up footnotes, page progression direction, text direction, interactivity, and presentational MathML. See EPUB 3 Features for more information.
The structure of a version 3 EPUB differs from a version 2 EPUB. A version 3 EPUB includes a Package Document (.opf) and a Navigation Document (toc.xhtml). The Package Document includes all of the information about a book including Metadata, Manifest, and Spine. The Navigation Document includes information about how to navigate a book and includes the Table of Contents, Landmarks, and Page-list. In EPUB 3, the Apple Display Options file has been replaced with Layout Metadata in the Package Document. See Structure of a Version 3 EPUB.
Book Versioning
For EPUB 3 and Multi-Touch books, you can provide book versioning information when you publish a new version of a book previously published to iBooks. The updated book replaces the old book on iBooks and is available to future consumers. Customers who have downloaded the old version of the book will be notified that a new version is available for download, and if the customer chooses to download it, the new version will replace the prior version on their device. For Multi-Touch books, book versioning is built into iBooks Author version 2. In iBooks Author, when you publish a new version of a previously published book, you are asked to provide versioning information during the publishing process. For EPUBs, see Book Versioning in EPUBs.
Read Aloud Books
In Read Aloud books, the currently-playing text will highlight as it is read aloud. iBooks allows you to embed read aloud controls in the page of a book. With iBooks 3.0, you can define if the page turn style is automatic or manual for the embedded read aloud controls. See CSS Styling of Media Overlays for more information.
New to EPUB 3, the Package Document must include the duration of each Media Overlay as well as the duration of the narration audio for the entire book. See Adding a SMIL File and Audio File to an EPUB for an explanation.
Links
You can link directly to your book on iBooks from your own website, from online advertisements, or within a book. The linking structure can link by ISBN. See Linking Directly to Your Book in Apple Books for details.
To customize the style of the links, you can use CSS to define the color and style of the anchor element. If you customize the style, you must also include the specified-fonts layout metadata. See Defining Book Layout Metadata.
Images
Clarified image sizes for book cover art and images inside the book. Added support for Gaiji. See Interior Image Requirements for more information.
Screenshots
You can deliver up to five screenshots for a book.
Miscellaneous Changes
ibook.js has been changed to ibooks.js (and iBook JS to iBooks JS) to reflect the updated name. The iBooks namespace has changed to xmlns:ibooks="http://vocabulary.itunes.apple.com/rdf/ibooks/vocabulary-extensions-1.0/".