9 Things You Need to Know About ePub3
2. It's HTML5 "domesticated"
The Web has become the universal platform for content and information. Readers will definitely be discovering your content via the Web, and will increasingly expect to consume it directly in browsers. HTML5, the latest version of HTML, is the core of all modern Web browsers. But websites coded in HTML5 are a thicket of files, scripts, style sheets, images, etc., meant to be executed by browsers du jour, not archived, distributed to channel partners, or processed by workflows like your content must be.
An ePub 3 publication—fundamentally just HTML5, CSS (cascading style sheet), scripts and related Web content—bridges that gap, as it follows the ePub standard's rules that make it well-structured, navigable and able to be packaged as a single file. An ePub 3 publication is a portable document, which makes it browser- and cloud reader-ready, as well as suitable for distribution through reseller channels and on to reading devices and apps for offline consumption. ePub 3 content is also far easier for you and your partners to slice-and-dice and otherwise reuse via widely available off-the-shelf XML tools.
3. Now for fixed-layout as well as reflow
ePub 3 supports full CSS styling including "absolute positioning," as well as SVG ("Scalable Vector Graphics") which enable precisely formatted content in XML. While reflowable ePub remains the best solution for multidevice support, if your content is highly designed—think coffee table books, children's books, textbooks—you may want or need to take advantage of the options in ePub 3 for fixed-format support.
4. An express lane to engaging apps and websites
Custom apps can certainly be developed without utilizing standards. But designing around ePub 3 is a smart move. Consider one of the first popular book-as-apps, "iPhone: The Missing Manual" (O'Reilly Media). Under the covers, this App Store-distributed title is a thin veneer over an ePub-based reading system that utilizes the Webkit browser engine built in to iOS. This architecture frees the editorial and production teams to focus on the content and the mobile app developers to spend their (scarce and expensive) cycles on delivering a differentiated and engaging experience.