OPDS Catalogs changelog (0.9 to 1.0)

Overall the changes between OPDS 0.9 and 1.0 are relative minor, and migration of OPDS 0.9 Catalogs to 1.0 should require minimal attention:

  • OPDS Catalogs are now more generic to open the door to other electronic content in the future (audio/video, comics etc.)
  • References to indirect acquisition have been removed.  Discussions will continue outside of the core specification in an information document.
  • There is a new "rel" value for Open Access.
  • Artwork relations have been modified.
  • The definitions and groups  feed-level relations have been morphed into: sorting relations, popular relation, previously acquired relations, and crawlable feed relation.
  • There is a notation relating to the use of DRM: "Publications in a format using Digital Rights Management SHOULD use a different value for the type attribute of the Acquisition Link than the same format without Digital Rights Management."
  • See additional specification language about the relationship between summary/content.
  • There is an informational Relax NG schema.

Overall, these numerate fairly minor modifications and should not require too much work to support them.

For a closer examination of changes, please consult the OpenPub wiki.

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OPDS Catalogs version 1.0 release

The open ebook community and the Internet Archive are pleased to announce the release of the first production version of the Open Publishing Distribution System (OPDS) Catalog format for digital content.  OPDS Catalogs are an open standard designed to enable the discovery of digital content from any location, on any device, and for any application.

The specification is available at: http://opds-spec.org/specs/opds-catalog-1-0.

Based on the widely implemented Atom Syndication Format, OPDS Catalogs have been developed since 2009 by a group of ebook developers, publishers, librarians, and booksellers interested in providing a lightweight, simple, and easy to use format for  developing catalogs of digital books, magazines, and other content.

OPDS Catalogs are the first component of the Internet Archive’s BookServer Project, a framework supporting open standards for discovering, lending, and vending books and other digital content on the web.

Brewster Kahle, digital librarian and founder of the Internet Archive, says, “As the audience for digital books grows, we can evolve from an environment of single devices connected to single sources, into a distributed system where readers can find books across the Web to read on whatever device they have.  OPDS Catalogs can help people find, buy, or borrow books, in the same way we use an open system to find Web sites, delivering the promise of a digital library to millions of readers around the world.”

OPDS Catalogs, which are easily produced from simple descriptive metadata, can be harvested by search engines and aggregated by online retailers; their design supports independent reading systems, bookstores, the development of portable bookshelves, and other applications facilitating the use of digital materials.

The Internet Archive makes available over 1 million public domain books in EPUB and PDF formats through OPDS Catalogs [opds].  IA’s titles are made available by Kobo Books, Amazon, and other distributors.


For publishers, OPDS Catalogs offers new possibilities for digital distribution and promotion.  “We're excited to support the OPDS standard," said Mark Coker, founder of Smashwords, a distributor of over 18,000 ebooks for 8,000 independent authors and publishers around the world.  "Our mission is to maximize the distribution opportunities for our authors.  By supporting OPDS Catalogs, we make it easy for multi-platform e-reading apps, devices and online bookstores to expose our catalog to millions of readers."

Dave Thomas, co-founder of Pragmatic Programmers, a leading publisher of programming books, says: “The OPDS Catalogs specification is a major step forward in opening up the distribution of electronic media to a broader world—publishers and readers can interact directly via the web and via reading devices to ensure that the most up-to-date content is available in real time.”


OPDS Catalogs, derived from Lexcycle’s Stanza application, allow an attractive presentation of book catalogs on mobile devices.    Well-known ebook expert Liza Daly, developer of the mobile reading application, Ibis Reader, says, “We’ve been impressed by how quickly OPDS Catalogs allow us to offer a collection of thousands of free and public domain books.  Now that users have access to a wide range of different reading systems, it's critical that the industry move toward broad distribution networks that mirror the web.”

The leading independent reading application for the Android operation system, Aldiko, also uses OPDS Catalogs.  Aldiko co-founder Tiffany Wong says: “The OPDS standard is a major step towards a truly open ecosystem for ebook distribution, providing the much needed glue between readers and a growing number of independent ebook sources. OPDS enables content providers to reach more readers and enables readers to discover more and more content. Thanks to the adoption of OPDS, Aldiko users are not limited to content from a single ebookstore. Instead, they can access thousands of free and commercial content from different ebook catalogs right within a single application. Currently, Aldiko users are downloading over 1.2 million books every month through OPDS catalogs.”


For libraries of all sizes, OPDS Catalogs can permit library patrons to access digital books and other materials without having to visit a library website.  In a special report [pdf] released in July 2010 on ebooks for public libraries, the Council of State Library Agencies (COSLA) endorsed the exploration of OPDS Catalogs.  The leader of the COSLA task force, Oregon State Librarian Jim Scheppke, writes: “State librarians across the country have been looking for ways to improve how library users discover and use library resources, especially e-books. In Oregon, and in other states I'm sure, we look forward to evaluating the potential of OPDS Catalogs as a basis for these improvements.”

OPDS Catalogs can be used to make data from one site available to others.  "There is clear demand for enhancing library catalogs around the world with information about ebooks," says George Oates, the project lead for Open Library.  "We're looking forward to using OPDS Catalogs to help libraries supplement their own catalogs with ebook records."


References for the OPDS Catalogs specification and opportunities to participate in the development of the Catalog project and upcoming work are located on this website.

For additional information, please contact Peter Brantley at peter [at] archive ORG, or Keith Fahlgren at keith [at] threepress ORG.

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OPDS v1.0 DRAFT – rfc

On behalf of the OPDS community, I am thrilled to announce that the draft OPDS 1.0 specification of the BookServer OPDS Catalog is available for review.

We are soliciting feedback and comments on this version 1.0 draft.

Please submit all critiques or comments to the OPDS mailing list, or add an issue to the OPDS project site by Tuesday, 17 August 2010.

Version 0.9 the OPDS Catalog specification was published on 25 May 2010.

What are OPDS Catalogs?

OPDS stands for Open Publishing Distribution System.  OPDS enables the aggregation, distribution, and discovery of books, journals, and other digital content by any user, from any source, in any electronic format, on any device. The OPDS Catalogs specification is based on the Atom syndication format and prioritizes simplicity and speed.

Today, OPDS Catalogs power many existing, in-production software systems and distribution between ebook reading systems, publishers, and distributors. Feedbooks, for example, already distributes more than 2 million ebooks every month using its OPDS Catalogs and ebook readers like Aldiko, Stanza, QuickReader, FBReader, Ibis Reader, and others already support the evolving specification. Publishers and libraries have been early adopters of OPDS Catalogs as the specification has evolved toward 1.0.

OPDS Catalogs are the first component in the Internet Archive’s BookServer Project.

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OPDS Catalog 0.9 Specification Published

On 25 May 2010, the OPDS Catalog 0.9 specification was published and is now available at: http://opds-spec.org/specs/opds-catalog-0-9. This first formal release of the specification, timed to coincide with IDPF Digital Book 2010 and BookExpo America, starts our 60 day comment and review period before the stable 1.0 release, which is scheduled to be published 26 July 2010.

If you've found flaws with the specification or other work or have criticisms or comments, please add a new issue in the issue tracker.

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OPDS 0.9 Draft call for comments

OPDS (Open Publication Distribution System) was first launched approximately one year ago, and today the OPDS community is very pleased to announce a call for comments on the first draft spec version, 0.9.

The OPDS Catalogs 0.9 draft is ready for public review and we are soliciting feedback and comments.

Please submit any and all critiques or comments to the openpub mailing list or add an issue on our project page by 19 May 2010.

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