EPUB

Added and/or improved in EPUB3:

Content Documents

• HTML5: EPUB 2 supports XHTML 1.1 and DTBook. With the support of the XML propoerties of HTML 5 in EPUB 3, it is now possible to use more detailed semantic markup (e.g. use section, aside, figure).
• Semantic Inflection: A new epub:type attribute, when added to HTML 5 markup, defines the precise nature of structural markup, in line with the publisher intended book semantics.
• Navigation: EPUB3 defines a new human-and-machine readable grammar for the navigation document, based on the HTML 5 nav element. It replaces the EPUB 2 .ncx file which now deprecated.
• SVG documents: They can now appear directly in the spine (they no longer need to be nested within an xhtml file).
• MathML: The XML markup language dedicated to the presentation of mathematical notations is now a first class citizen in EPUB publications.
• Content switching: It has been simplified by having its processing model defined so that it does not require document preprocessing.

Navigation

• EPUB Navigation Documents: supersedes the NCX grammar used in EPUB 2.

Linking

• Linking: Linking schemes have been added. At the moment there’s only one available. Please refer to the Canonical Fragment Identifiers.

Scripting and Interactivity

• Interactivity: You can now script scrollbars, photo galleries, text popups, etc… using Javascript code.
• Triggers: Trigger is an element included in HTML5 for EPUB that allows declarative bindings of activation events (such as “play”, “pause” for an audio event)
• Bindings: You can now script your own handles for uncommon media files.

Styling and Layout

• Fixed Layout: see Reflowable vs Fixed Layout.
• Added modules from CSS3: It also includes alternate style tags, allowing the creation of custom viewing modes, such as day, night, etc.
• Embedded Fonts: EPUB 3 requires Reading Systems to support the OpenType and WOFF font formats for embedded fonts in conjunction with the CSS @font-face rules.
• Font Obfuscation: A new normative section on Font Obfuscation [OCF3] has been added the Open Container Format specification.

Rich Media and Speech

• Media overlays: With the possibility of adding audio, EPUB includes a way to synchronize it with the text.
• Text-to-speech: The possibility of a text-to-speech ebook is now implemented (using properties such as SSML attributes in XHTML content documents.
• Audio and video: EPUB 2 has support for raster images only. Thanks to HTML 5, EPUB 3 publications can reference audio or video assets via the audio or video tags, and therefore audio and video assets can be natively processed by modern browser engines.

Meta Data

• Publication Metadata and Identity: New but mandatory metadata has been added, dcterms:modified Date on which the resource was changed.
• Resource Metadata: there are new properties attributes on the Package Document, allowing the declaration of new metadatas about the resources.

Containment

• Remote Resources: EPUB 3 added new restrictions to the resources not located in the container. Please see changes to noted here.
• Whitespace in MIMETYPE file: The restriction against trailing whitespace has been removed.
• Disallowed characters: The OCF list of disallowed characters has been extended.

Removed or changed:

• DTBook File format similar to HTML, with special regard to the requirements of the visually impaired.
• Out-of-Line XML Islands an XML document that is not authored in a Preferred Vocabulary.
• Tours A tag to mark points of interest in a publication
• Filesystem Container
• Guide
• NCX Part of the specification for digital talking book DTB and is used in ePub documents to define the Table of Contents (TOC).
• 2.0.1 meta element meta element annotating the version