Readium Project Goals

The fundamental goal of the Readium project is to produce a set of robust, performant, spec-compliant reading system toolkits that support digital publishing formats (e.g. EPUB, Web Publications etc.) and can be deployed in browsers or built into native apps on iOS, Android or the desktop.

Primary Focus

The project’s primary focus is to provide a set of software building blocks (software development kits as well as utilies and glue that faciliates the construction of a wide spectrum of robust, performant reading systems.

It is the intent to enable a platform that can be easily adapted to supporting a variety of “digial publishing formats”, including:

  • EPUB 2.x and 3.x
  • Audio books
  • Image-based books (e.g. Manga, etc.)
  • Web Pub

There are currently (early 2019) four target platforms:

  • iOS
  • Android
  • Desktop (e.g. MacOS, Windows, Linux)
  • Browser-based

In addition, developers are of course more than welcome to adapt the Readium toolkits to other platforms, but the four above are the primary focus of Readium development at present.

It is important to emphasize that Readium strives to network and coordinate with other open-source efforts, most notably the European Digital Reading Lab (EDRLab) which is the European arm of Readium. EDRLab is not only a major participant in the Readium effort, but is also the lead and driver for the Licensed Content Protection (LCP) system.

Open Source

Readium is a true open-source project, permissively licensed under the 3-part BSD license. This licensing approach applies to ALL the code developed in the Readium project. This includes not only the current development projects but also the legacy software (Cloud Reader, Chrome app and Readium C++ SDK)


Readium strives to create a courteous, welcoming environment that feels approachable to newcomers. We maintain both public chat rooms (via Slack) and a public mailing list ( where the ideas of contributors both new and old are heard and discussed with equal weight. For more information see the Communication page here.

Standards Compliance

Readium aims for compliance with all the relevant W3C specifications, including EPUB as well as other emerging digital publishing format such as audio and comic books.

In order to achieve this, many members of the Readium community are active participants in a wide variety of W3C working groups (e.g. working, community and business groups for both EPUB and WebPub).

In addition to helping to develop the specifications themselves, Readium has and will continue to provide feedback to the various W3C groups on developing and testing implementations of the new emerging standards.

EPUB and related formats are expected to have longevity and to be interoperable across multiple, indirect distribution channels, and reliably manipulated by intermediate workflows. Being a comprehensive reference system, Readium places a high priority on compatibility with the EPUB specifications as well as new emerging standards, such as WebPub.


Providing access to reading system functionality for ALL users is a critical part of the Readium goals. To achieve this, great efforts are made as part of the Readium development to provide access to the content for all users, whether that is through using CSS to provide a better reading experience or tight integration with system level accessibility affordances such as VoiceOver and similar technologies.


The Readium development community strives to keep the code base up to date and with a high degree of stability. This means that crashes, hangs and regressions are given the highest priority for fixes and releases. Readium closely tracks reported issues from both internal testing and external forums. Members of the Readium community are strongly encouraged to report new issues, update ongoing problems and foster communication aimed at provide a more stable development and execution environment.


Maintaining and improving execution speed and memory use is an important goal, and one that Readium aims to achieve. However, there is a dynamic balance to be struck as Readium also aims to provide a complete reference system for both EPUB and other emerging W3C standards.


Protecting users from security violations is critical. Insofar as possible we strive to fix security issues promptly to protect users and maintain their trust.


To the extent that Readium features affect the user experience, we want them to work in accordance with good human interface design principles, and to mesh well with platform-native HI conventions. Furthermore, we strive to integrate with platform accessibility features to allow access for all users, including those with disabilities.


Governance of the project is by a seven-person board of directors which takes direction from the members of the Readium Foundation as well as the grass-roots needs and requests from the contributors (who need not be members of the Foundation).


The above set of goals are a lot to bite off, so we consider the following out of scope for the project:

  • Readium is a reference system and engine, not a commercial Reading System.
  • We have no plans to develop or host a full-featured commercial-quality application based on Readium. Others are welcome to do so, of course.
  • Readium is not the solution to every problem. We focus on handling EPUB/WebPub publications, not complete solutions to every imaginable technology need.