The Open Publication Distribution System (OPDS) is an application of the Atom Syndication Format intended to enable content creators and distributors to distribute digital books via a simple catalog format. This format is designed to work interchangeably across multiple desktop and device software programs.
The idea of this system is to provide a format that can be used by eBook readers or even a dedicated eBook reader devices with Internet access to be able to search, discover, and download eBooks from online eBook catalogs. The system requires an RSS style processor that works with the distribution system to display choices with descriptions for the user to download. It could also provide the ability to purchase eBooks or other files. Supporting this format would be sufficient for wireless capable devices that did not include a Web Browser or that wanted to standardize the user interface experience from multiple sites.
 Online OPDS Catalogs
 (Mainly) English
- All Romance eBooks: http://allromanceebooks.com/epub-feed.xml
- Baen eBooks (formerly Webscriptions.net): http://www.baenebooks.com/stanza.aspx
- BooksOnBoard: http://www.booksonboard.com/xml/catalog.atom
- ePubBud Children's books: http://www.epubbud.com/feeds/catalog.atom
- Feedbooks: http://www.feedbooks.com/catalog.atom
- GitBook: https://www.gitbook.com/api/opds/catalog.atom
- Internet Archive: http://bookserver.archive.org/catalog/
- ManyBooks: http://www.manybooks.net/opds/index.php
- Ludwig von Mises Institute (Libertarian think tank): http://mises.org/catalog/
- O'Reilly: http://opds.oreilly.com/opds/
- Plough Publishing: http://www.plough.com/ploughCatalog_opds.xml
- PragPub Magazine | The Pragmatic Bookshelf: http://pragprog.com/magazines.opds
- Project Gutenberg: http://m.gutenberg.org/ebooks/?format=opds
- SamEnrico: http://www.samenrico.com/
- Tuebl: http://www.tuebl.ca/catalog
 (Mainly) Chinese
- Shucang: http://www.shucang.com/s/index.php , http://www.shucang.org/s/index.php
- SNDA YZSC: http://opds.yzsc.com.cn
 (Mainly) French
- Revues.org: http://bookserver.revues.org/
- Ebooks libres et gratuits: http://www.ebooksgratuits.com/opds/
- Atramenta: http://www.atramenta.net/opds/catalog.atom
- YouScribe: http://opds.youscribe.com/Catalog/catalog.xml
- eForge: http://eforge.eu/OPDS/_catalog/index.xml
- Atoll Digital Library: http://atoll-digital-library.org/opds/
 (Mainly) Polish
- Legimi - digital content delivery platform: http://www.legimi.com/opds/root.atom
- Wolne Lektury Internet Library: http://www.wolnelektury.pl/opds
 (Mainly) Russian
- Электронные книги на русском: http://iknigi.net/opds
- Флибуста Книжное братство: http://flibusta.is/opds
- Либрусек (Русские электронные книги): http://lib.rus.ec/opds
- Гейт OPDS для журнала "Самиздат": http://opdshome.uo1.net/samlib/
Book Library: http://books.vnuki.org/opds.xml(dead as 10/7/14)
- ePubBooks.ru (Русские электронные книги): http://www.epubbooks.ru/index.xml
- zone4iPhone.ru (Русские электронные книги): http://www.zone4iphone.ru/catalog.php
- КулЛиб (Русские электронные книги): http://coollib.net/opds
- OPDS Start Page (Contains links to many other OPDS catalogs): http://opdshome.uo1.net/
 eBook Reading Software Supporting OPDS
- Bookviser: - EPUB/FB2/TXT reader and OPDS client for Windows Phone and Windows 8
- Coffee Reader: - txt/ePub/Fb2/Mobi reader for Windows Phone 8 available on Windows Phone Marketplace.
- Cool Reader: - Only in Android version.
- Document Viewer: - PDF, epub, FB2, CBZ for Android available in Google Play store and F-Droid.
- eBook Search App: - iPhone/iPad app. Download free books from major catalogs to iBooks, Kindle, Nook, or your favorite eBook reader app. Available on iTunes app store.
- eBook Search PRO App - iPhone/iPad app. Download free books from major catalogs to iBooks, Kindle, Nook, or your favorite eBook reader app. Available on iTunes app store.
- EPUBReader: - All devices and OS supporting Firefox and SeaMonkey Web Browsers
- FBReader: - All devices with network access.
- iBouquiniste: - iBouquiniste for iPad, iPhone, and iPod Touch. Supports FB2, ePub. Available on iTunes app store.
- IDEAL Group Reader: - ePub reader for the Android available in the Google Play store.
- Infinite Book Reader: - eBook reader for the iPad.
- Mantano Reader: - ePub and PDF reader for Android.
- Marvin: - ePub reader for the iPad, iPhone, and iPod Touch. Available on iTunes App Store.
- MegaReader: - Highly customizable eBook reader for the iPad, iPhone, and iPod Touch with Heads Up Display. Available on iTunes app store.
- Moon+ Reader Pro: - ebook reader for Android devices.
- Ouiivo Reader: - EPUB reader and OPDS client for iPhone and iPod Touch
- QuickReader: - The Speed Reading eBook Reader for the iPad, iPhone, and iPod Touch. Available on iTunes app store.
- Stanza: - Free EPUB reader with OPDS support.
 Software Supporting OPDS
- Calibre2opds compatible software - Calibre software is free
- personalbookspace: - A fee-based personal online catalog service
 OPDS Catalog Generation
- calibre2opds generates OPDS and HTML catalogs from the ebooks database of Calibre.
- COPS generates OPDS and HTML catalogs on your server, from your Calibre library. Needs PHP and file access to the Calibre library.
- Lucicat generates OPDS and HTML catalogs on your server. Needs PHP/MySQL to run. As of mid-2012, the author has removed it from his website and it is unavailable, but here is a mirror
- OPDS catalog is an app for the Owncloud personal cloud server, enabling users to publish a sub-tree of their personal filesystem as an OPDS feed
- Pathagar - Pathagar is a book server written in Python Django. It serves book catalogs through a web interface and OPDS feeds for use with clients including the Get Books activity on the Sugar Learning Platform, largely used on One Laptop per Child laptops. Book uploads, tagging, grouping and other management is done through the web interface. Bulk uploads are done using JSON and CSV.
- Simple OPDS - Simple OPDS server for Linux platform written on python3
- TinyOPDS - lightweight and simple OPDS server for the home use, needs Windows OS plus .NET 4.0 (client profile) or Linux OS plus Project Mono * Pathagar - Pathagar is a book server written in Python Django. It serves book catalogs through a web interface and OPDS feeds for use with clients including the Get Books activity on the Sugar Learning Platform, largely used on One Laptop per Child laptops. Book uploads, tagging, grouping and other management is done through the web interface. Bulk uploads are done using JSON and CSV.
- Ubooquity is an ebooks/comics server which allows access to your collection through web pages or OPDS feeds. Needs Java.