Copyright © 2005 O'Reilly Media, Inc. All rights reserved.

Printed in the United States of America.

Published by O'Reilly Media, Inc., 1005 Gravenstein Highway North, Sebastopol, CA 95472.

O'Reilly books may be purchased for educational, business, or sales promotional use. Online editions are also available for most titles ( For more information, contact our corporate/institutional sales department: (800) 998-9938 or

Nutshell Handbook, the Nutshell Handbook logo, and the O'Reilly logo are registered trademarks of O'Reilly Media, Inc. Developing Feeds with RSS and Atom, the image of an American kestrel, and related trade dress are trademarks of O'Reilly Media, Inc.

Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and O'Reilly Media, Inc. was aware of a trademark claim, the designations have been printed in caps or initial caps.

While every precaution has been taken in the preparation of this book, the publisher and authors assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein.


    This book is about RSS and Atom, the two most popular content-syndication technologies. From distributing the latest web site content to your desktop and powering loosely coupled applications on the Internet, to providing the building blocks of the Semantic Web, these two technologies are among the Internet's fastest growing.

    There are millions of RSS and Atom feeds available across the Web today; this book shows you how to read them, how to create your own, and how to build applications that use them. It covers:

    • RSS 2.0 and its predecessors

    • RSS 1.0 and the Semantic Web

    • Atom and the latest generation of feed technology

    • How to create and parse feeds

    • Extending RSS and Atom through modules

    • Using RSS and Atom on the desktop, on the Web, and in the enterprise

    • Building RSS- and Atom-based applications


      This book was written with two somewhat interrelated groups in mind:

      Web developers and web site authors

      This book should be read by all web developers who want to share their site with others by offering feeds of their content. This group includes everyone from webloggers and amateur journalists to those running large-budget, multiuser sites. Whether you're working on projects for multinational news organizations or neighborhood sports groups, with RSS and Atom, you can extend the reach, power, and utility of your product, and make your life easier and your work more productive. This book shows you how.


      This book is also for developers who want to use the content other people are syndicating and build applications that produce feeds as their output. This group includes everyone from fan-site developers wanting the latest gaming news and intranet builders needing up-to-date financial information on the corporate Web, to developers looking to incorporate news feeds into artificially intelligent systems or build data-sharing applications across platforms. For you, this book delves into the interpretation of metadata, different forms of content syndication, and the increasing use of web services technology in this field. We'll also look at how you can extend the different flavors of RSS and Atom to fit your needs.

      Depending on your interests, you may find some chapters more necessary than others. Don't be afraid to skip around or look through the index. There are all kinds of ways to use RSS and Atom.