All of the formal versions of the OPDS Catalog specifications are available on the specifications page.
What are OPDS Catalogs?
OPDS Catalogs enable 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.
Are there any current implementers of this standard?
The OPDS Catalog 1.1 specification is based on a lot of existing, in-production software and collaboration between ebook reading systems, publishers, and distributors. Feedbooks, for example, distributes more than 3 million ebooks every month using its OPDS Catalogs (http://www.feedbooks.com/catalog.atom) and ebook readers like Aldiko, Bluefire Reader, 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 1.1.
- Feedbooks (Thousands of free books & books from major publishers in the US, France & Germany, http://www.feedbooks.com/catalog.atom)
- Internet Archive (1.8 million free books, http://bookserver.archive.org/catalog/)
- O'Reilly Media (hundreds of technical ebooks, http://opds.oreilly.com/opds/)
- The Pragmatic Programmers (http://pragprog.com/catalog.opds)
- Revues.org (http://bookserver.revues.org)
OPDS Catalogs are the first component in the Internet Archive’s