EPUB-WEB and Open Annotation
A portable document is a collection of content items (e.g. pages, chapters, modules, articles) structured as a single, self-contained logical unit. Individual items can consist of text, images, graphics, possibly interactive mathematical or chemical formulae, as well as audio and video. These documents by definition have a default, linear “reading order”, however the user may choose to skip around in the content just as with a book on paper; alternatively, interactive aspects of the content may alter the reading order on behalf of the user.
Several portable document formats exist. The only vendor independent and HTML based format is EPUB [EPUB3], which emphasizes a dynamic determination of content presentation and a closer alignment with the Open Web Platform. EPUB can represent reflowable contents as well as sequences of final-form fixed pages; depending on the publication type, an EPUB document may default to one of those. EPUB is built on Web Standards, and the individual items that make up an EPUB publication are identical to types of content on a Web site: [html5], [svg], [css21], [ECMAScript], [JPEG] and [png] images, etc.
EPUB can be viewed as simply defining a specialization of Web content that assures that a collection of content items has the needed properties of completeness and logical structure, and does so in a standard way that other processing tools and services can reliably create, manipulate, and present such collections.
EPUB can be considered to be at a tipping point. EPUB has been broadly adopted globally for trade ebooks, and is starting to gain adoption among textbook publishers as well as corporate marketing departments. However, EPUB has largely been seen as an “offline” format up until now. Various browser extensions supporting EPUB exist (Readium in Chrome, EPUB in Firefox, et al.). Other solutions exist for delivering EPUB files in browsers (Readium-Cloud, EPUB.js, Safari Books Online, et al.). Browser- and cloud-based solutions require relatively complex server and/or client software. In many cases browser- and cloud-based solutions depend on a proprietary transformation of the packaged EPUB files into formats more suitable to network delivery. A focused effort to make EPUB a first-class Open web Platform citizen will result in significant reduction in the complexity of deploying EPUB content into browsers for both online and offline consumption. Further, this focused effort will increase the momentum of EPUB and associated web adoption across communities who are looking for an open, non-proprietary, next-generation portable document format.
The broader Web Platform can also be considered to be at a tipping point. Mobile platform web site use is diminishing in favor of native applications. Hybrid applications that use web content alongside native application technology, and web-technology-based system applications are growing. The specific means of delivering hybrid and web-technology-based system applications is currently proprietary to specific applications frameworks and/or browser platforms. The point of EPUB-WEB is to increase problem solving momentum in package, metadata, and offline support applicable to both portable documents and installed applications. Open and native solutions to replace proprietary packaging, metadata, and offline support are intended to ensure the broadest possible general adoption of the Open Web Platform.
This white paper introduces EPUB-WEB (CC BY), a vision for the future of digital publishing that is based on a fully native representation of documents within the Open Web Platform. EPUB-WEB achieves full convergence between online and offline/portable document publishing: publishers and users won’t need to choose one or the other, but can switch between them dynamically, at will. The document is merely a public working draft of a potential specification.
One of somewhat related efforts is Open Annotation – also a W3C initiative. In general terms, an Annotation expresses the relationship between two or more resources, and their metadata, using an RDF graph. The Open Annotation Core framework explains how to identify and describe the related resources, and how to provide information concerning the creation and intent of the Annotation.
This document from W3C describes the set of use cases generated for Annotation and Social Reading within the W3C Digital Publishing Interest Group, in coordination with the Open Annotation Community Group. Open Annotation in EPUB defines a profile of the W3C Open Annotation specification [OpenAnnotation] for the creation, distribution and rendering of annotations for EPUB Publications.
These efforts for interoperability of content and metadata leveraging the web standards are definitely beneficial for global learners and open learning.