Announcing Readium.js, a JavaScript library for browser-based EPUB 3 reading

May 30, 2013
Today announced that the Readium Web project is being refactored to deliver a JavaScript library for browser-based EPUB 3 reading. Currently in early alpha, the new Readium,js is a lightweight, compact (20KB compressed) client-side library. When complete, Readium.js will enable easy deployment of any EPUB publication from any web server to all modern browsers (mobile and desktop). An initial demo of online reading of EPUB 3 utilizing Readium.js is live at For preliminary documentation and to get the code, visit .
Readium.js is freely available from the Readium Foundation as open source software (BSD licensed). Readium.js packages together a modular collection of JavaScript modules focused on online deployment of EPUB content, under the umbrella project name "Readium Web Components". Readium Web Components can be reassembled and configured by developers in a variety of ways to create completely custom reading experiences. And with Readium.js in its default configuration, deploying an EPUB 2 or EPUB 3 file for online viewing will be as easy as unzipping it onto any static Web server and simply adding the readium js file and additional libraries, with no server-side programming or custom client-side scripting required.
Readium.js is a refactoring of the EPUB 3 reference system developed over the past year, which was initially deployed as a Google Chrome browser extension, (available at: and was subsequently adopted as the nucleus of several browser-based “cloud” readers, including the Benetech Bookshare Web Reader. The Readium Chrome web app supports, as will Readium.js when complete, all major features of the latest version of EPUB 3, including dynamic pagination of reflow content as well as fixed-layout content, full HTML5 with JavaScript interactivity, audio, video, media overlays, and embedded fonts. Readium.js leverages several widely adopted JS libraries including jQuery and Backbone.js. Readium js is in early beta, with a number of organizations and individuals collaborating to develop and improve it, and its features and API are subject to change. Readium Foundation would like to acknowledge the contributions of Evident Point to overall architecture of Readium Web and Readium js, and of Benetech in developing accessibility features and initial work on cross-browser support.
Readium.js and other projects:  the Readium Chrome Packaged App (available from the Chrome Web Store) remains a supported configuration of the Readium Web initiative, with over 60,000 users, and will be updated in the near future to be built on the refactored Readium Web Components. The Readium SDK project ( is a complementary initiative under active development, focused on delivering a high-performance EPUB 3 engine for native apps on desktops and mobile devices. Readium SDK is utilizing several sub-components of Readium Web Components.
About Readium Foundation is a Delaware 501(c)(6) non-profit membership corporation, established in 2013 to develop commercial-grade open source components to advance global digital publishing for EPUB and the Open Web Platform. Over two dozen organization members have already joined Readium Foundation. To learn more about how your organization can become a member of Readium Foundation, see: . Individual developers and organizations are also encouraged to contribute to projects. For more information, visit: