EPUB Update by Bill Kasdorf, VP-Apex

December 11, 2013 – As EPUB 3 turns two years old—no “terrible twos” jokes, please—there is more activity than ever around this fundamental standard. Too much, in fact, to present here in detail other than a bulleted-list summary (with links to more detailed discussion).

• EPUB 3 Goes ISO. EPUB 3.0 is in the process of becoming an ISO technical specification. This is important for many reasons, but two stand out: it puts a truly global seal of approval on it, and it makes EPUB much more likely to be officially adopted by various institutions, organizations, and countries.
• Yes, It Works. Despite its reputation for insufficient adoption, most features of EPUB 3 are now implemented in leading reading systems, from iBooks and Kobo for consumer books, to CourseSmart and VitalSource for textbooks, to browsers like Firefox, plug-ins like Readium for Chrome, and tools like BlueGriffon. Even Amazon (yes, Amazon!) wants EPUB 3 as input for KindleGen, which produces its KF8 format from EPUB 3 files. And many of the activities listed below are helping to accelerate the pace of adoption. Many publishers are now making EPUB 3 (ideally, with fallbacks to EPUB 2) their standard format for ebook delivery.
• But It Needs to Work and Be Used Better. To address the frustrating “chicken-and-egg” problem—reading systems haven’t implemented certain features of EPUB 3 because they don’t see the demand for them in the files they get from publishers, and publishers don’t use those features in their files because they aren’t implemented widely in reading systems—the Association of American Publishers (AAP) recently convened a group of publishers, reading system developers, and accessibility professionals to help focus attention on the near term: priorities for reading system implementation of EPUB 3 features, and best practices for publishers in the creation of EPUB 3 publications. The White Paper reporting on this “AAP EPUB 3 Implementation Initiative” summarizes the conclusions, provides links to many helpful resources, and emphasizes the need for further work involving many other organizations to get the EPUB 3 ecosystem in better alignment.
• We’re Working On It! EPUB 3 was designed as a modular standard so it could be augmented and refined over time. An update, EPUB 3.0.1, was just posted for public review and should be finalized by the end of the year. Although this update mostly clarifies some of the wording in the spec (with no harm to the existing EPUB 3.0 spec), it also includes some helpful new things. One highlight is that it makes it easier to add new EPUB structural semantics vocabularies and terms, which will enable groups that need specialized vocabularies—e.g., for indexes, textbooks, magazines—to get what they need in EPUB more quickly. Another highlight is the integration of the specs for Fixed Layout EPUBs, which had previously been in a separate informational document.
• Indexes, Dictionaries, and Glossaries. Over the past year or so, two working groups convened by the IDPF have been developing specs for using EPUB to create truly dynamic, digital-era indexes (think of an index as providing intellectual, topic-based navigation, to complement simple search and structural TOC-based navigation) and to provide both standalone dictionaries and to incorporate dictionary and glossary content and functionality in EPUBs. The finished draft of the index specification was recently released for public review and is expected to be finalized by the end of the year in synch with the EPUB 3.0.1 update. The spec for dictionaries and glossaries is under development.
• Advanced/Hybrid Layout. Another working group, known as Advanced/Hybrid Layout (AHL), is addressing the need for more complex layouts—for example, combining fixed layout and reflowable layout in a single document, and handling comics, manga, and graphic novels. One major result of this will be the ability to provide multiple renditions of a single EPUB in a single .epub container—for example, renditions with different layouts for landscape and portrait orientations, or renditions in different languages. It will also provide a means to address and manipulate regions of a page—for example, the panels in a manga or comics page—so they can be rearranged to fit various screen dimensions and aspect ratios.
• Annotations. A new working group devoted to Open Annotations in EPUB has recently been formed. This will be extremely important to scholarly publishing. It’s a complex issue for which work is only beginning. SSP’ers are encouraged to participate so that the needs for annotation and citation in scholarship are well represented.
• EPUB Profiles. The EPUB 3 standard is deliberately accommodating and agnostic. It’s for all kinds of publications, not just books, and its markup and metadata are deliberately designed not to be specific to any particular type of content or publication. This has prompted the development of more focused “EPUB Profiles” that specify how best to apply EPUB 3 to address the needs of specific interest groups. Currently, profiles for textbooks and magazines are under development. These are described in the following two items below.
• EDUPUB—EPUB for Education. The IDPF and Pearson convened a meeting in Boston on October 29–30, 2013, to begin the process of assessing how best to use EPUB 3 for the delivery of educational content. This is expected to lead to the development of an “EPUB Profile” for educational content, particularly textbooks, to take advantage of the semantics, multimedia, scripting, and to add other advanced features that EPUB 3 offers. These developments will establish an open, widely agreed-upon standard that will help make educational content more dynamic and interoperable. An article describing this more fully is available from Publishing Business Today.
• OpenEFT—Magazines for Tablets. IDEAlliance, the chief standards organization for the magazine industry, recently developed the initial release of their OpenEFT specification for the delivery of magazines optimized for tablets. (EFT stands for “Enhanced for Tablets.”) In doing so, they conformed as much as possible to the EPUB 3 spec. For example, the packaging format in OpenEFT is the EPUB 3 packaging format. In a great example of industry collaboration, IDEAlliance and the IDPF have worked together to avoid conflicts between OpenEFT and EPUB, and a joint task force is working toward the goal of refining OpenEFT to become a valid EPUB Profile for magazines.
• The Compliance Test Suite and the New BISG EPUB 3 Grid. BISG’s EPUB 3 Support Grid, which documents what features of EPUB 3 are implemented in which reading systems and devices, has become an extremely popular resource. Now, BISG and the IDPF are partnering to create a next-generation version based on the IDPF’s new EPUB 3 Compliance Test Suite, a system for rigorous, formal testing and reporting of reading system feature compliance. The result is expected to be a dynamic web resource that will enable much more detailed, real-time monitoring of the evolution of the EPUB 3 ecosystem.
• The Readium Foundation and Readium SDK. The open-source, Webkit-based Readium plug-in for Chrome has become, as intended, the reference platform by which publishers test their EPUBs. This is an instance of Readium Web, an EPUB 3 rendering engine for browser-based cloud readers. To build on this success, the Readium Foundation was recently formed to pursue and support the creation of open-source software (primarily based on JavaScript), called Readium SDK, to facilitate the development of EPUB 3-compliant platforms, apps, and devices that are not necessarily browser-based.
• We’ve Got the Attention of the W3C! The Web was originally developed for making content available via Web browsers. The requirements for more formal publications like journals and books were not, frankly, given much thought. But now, it’s apparent that the Open Web Platform on which EPUB 3 is based—the suite of 100-some standards like XML, HTML, CSS, MathML, SVG, and JavaScript—have become essential for publishing online, in ebooks, in apps, and in some cases even in print. In response, the W3C (the governing body for Open Web standards) has convened a Digital Publishing Interest Group to identify ways in which those standards can be improved for publishing of all sorts.

Lots of action! It’s clear that EPUB 3 has become an essential standard for publications of all sorts. The EPUB 3 ecosystem has matured to the point where publishers can now confidently use it. And the resulting surge in support has made it not only desirable, but imperative, to continue to improve it. It’s extremely encouraging to see not only the level of activity but the level of collaboration involved in doing just that.

Bill Kasdorf, Vice President and principal consultant of Apex Content Solutions, is an active participant in many of the initiatives discussed in this post. He is Metadata Subgroup Lead of the IDPF’s EPUB 3 Working Group, an active participant in the Indexing Working Group, and a member of the W3C Digital Publishing Interest Group. He is Chair of the BISG Content Structure Committee, which publishes the BISG EPUB 3 Grid and related publications. He is a member of the IDEAlliance working group that developed PSV, the PRISM Source Vocabulary for magazines, and is a member of the joint IDEAlliance/IDPF OpenEFT/EPUB Alignment Technical Task Force. He serves on the Publishing Business STM Advisory Council, and was the principal facilitator for the AAP EPUB 3 Implementation Initiative. A Past President of SSP and an active member of both the SSP Annual Meeting Program Committee and the SSP Organizational Collaboration Committee, Bill was the recipient of SSP’s Distinguished Service Award in 2005.