EPUB has turn out to be a lot part of the worldwide publishing ecosystem that one might be forgiven for taking it without any consideration, not realizing that its specs, which had been first issued by the IDPF in 2007 and up to date since 2017 by the Worldwide Net Consortium (the W3C), had not, actually, been formal W3C requirements.
Till now. On Might 25, the W3C—the worldwide requirements physique for such elementary internet applied sciences as XML, HTML, CSS, and scores of different requirements that energy at present’s digital world—printed EPUB 3.3 as a proper W3C Suggestion. And in what I’d characterize as deft sleight of hand, EPUB 3.3 manages to be each dramatically completely different from its predecessors whereas being “backward suitable,” guaranteeing that all the thousands and thousands of EPUB 3.2s already printed are nonetheless legitimate.
Three specs in a single
Essentially the most putting distinction between variations is straight away obvious. EPUB 3 is not one specification, like all the earlier variations, however three.
• EPUB 3.3 specifies how all EPUB 3 paperwork are structured and encoded. It’s known as the “authoring” specification: the spec that creators of EPUBs ought to observe.
• EPUB Studying Methods 3.3 specifies how the programs and software program that ship and render EPUBs ought to interpret the spec.
• EPUB Accessibility 1.1 specifies the tagging and metadata that can guarantee than an EPUB 3 is absolutely accessible.
It is a very helpful restructuring. The earlier EPUB specs didn’t clearly distinguish between these three vital contexts. They principally centered on authoring, with solely just a little details about accessibility and virtually none on how studying programs ought to behave. The brand new EPUB 3.3 spec was considerably rewritten to make issues a lot clearer.
Testing, testing, testing
One other actually vital side of the event of the brand new spec is that each function of it was totally examined. That’s one of many necessities of a W3C Suggestion: there should be at the least two impartial implementations of each function of the spec or the function needs to be eliminated.
This accomplishes two elementary issues: clearly, that the given function really works in the actual world—however not by the way, that there have been at the least two impartial organizations that thought every function was definitely worth the hassle of implementing.
This isn’t trivial. One of many weaknesses of a few of the earlier variations of EPUB was that they included options that no person ever applied.
To turn out to be a suggestion, the spec additionally must go the W3C’s “horizontal assessment,” which affirms that it conforms to the necessities of accessibility, internationalization, safety, privateness, and alignment with the basic internet structure. This ensures that the spec can work for everyone, no matter capacity; that it may be utilized in languages all through the world; and that it really works and performs properly with internet applied sciences on the whole. All that is true of the brand new EPUB 3.3.
Assembly E.U. requirements
Key European members of the W3C’s EPUB Working Group conferred with the European Fee because the European Accessibility Act was being developed. Now finalized, the EAA requires, amongst many different issues, {that a} e-book can’t be bought within the E.U. as of 2025 if it isn’t obtainable in an accessible format. However it doesn’t present a lot particular steering as to what’s going to represent enough accessibility.
One strategy to know: the W3C has confirmed {that a} e-book obtainable in an EPUB that conforms to EPUB 3.3 (and particularly the EPUB Accessibility 1.1 Suggestion) will actually be thought of accessible—and thus saleable within the E.U.
The ecosystem is all set
Finish customers usually maintain again implementing a brand new specification, ready to ensure downstream applied sciences which are going to make use of it have caught up. The lengthy, deliberate, and really public growth course of for EPUB 3.3 has ensured that the ecosystem is prepared for it on day one. Virtually all the many 1000’s of producers and disseminators of EPUBs, from publishers and their pre-press and information conversion suppliers to the aggregators and retailers within the e-book provide chain, are depending on EPUBCheck, the software program that robotically checks an EPUB for conformance to the spec. Most retailers will merely reject any EPUB that doesn’t go EPUBCheck.
Due to the take a look at suite created for EPUB 3.3, the present model of EPUBCheck already conforms to it, and many of the provide chain has already applied it. The identical is true of Ace by DAISY, the accessibility checker that almost all producers of EPUBs use.
We’re good to go, people! EPUB 3.3 ought to be a agency, steady, and enormously helpful commonplace for a very long time to return.
Invoice Kasdorf is principal at Kasdorf & Associates LLC, a publishing consultancy. He’s a founding accomplice of Publishing Expertise Companions.
A model of this text appeared within the 06/26/2023 concern of Publishers Weekly below the headline: A Good Balancing Act