From Wikipedia, the free encyclopedia

A typical web feed logo

A web feed is a data format used for providing users with frequently updated content. Content distributors syndicate a web feed, thereby allowing users to subscribe to it. Making a collection of web feeds accessible in one spot is known as aggregation, which is performed by an Internet aggregator. A web feed is also sometimes referred to as a syndicated feed.

In the typical scenario of using web feeds, a content provider publishes a feed link on their site which end users can register with an aggregator program (also called a feed reader or a news reader) running on their own machines; doing this is usually as simple as dragging the link from the web browser to the aggregator. When instructed, the aggregator asks all the servers in its feed list if they have new content; if so, the aggregator either makes a note of the new content or downloads it. Aggregators can be scheduled to check for new content periodically.

The kinds of content delivered by a web feed are typically HTML (webpage content) or links to webpages and other kinds of digital media. Often when websites provide web feeds to notify users of content updates, they only include summaries in the web feed rather than the full content itself.

Web feeds are operated by many news websites, weblogs, schools, and podcasters.

Web feeds have some advantages compared to receiving frequently published content via email:

• When subscribing to a feed, users do not disclose their email address, so users are not increasing their exposure to threats associated with email: spam, viruses, phishing, and identity theft.
• If users want to stop receiving news, they do not have to send an "unsubscribe" request; users can simply remove the feed from their aggregator.
• The feed items are automatically "sorted" in the sense that each feed URL has its own sets of entries (unlike an email box, where all mails are in one big pile and email programs have to resort to complicated rules and pattern matching).

A "Feed Reader" is required for using Web Feeds. This tool works like an automated e-mail program, but no e-mail address is needed. The user subscribes to a particular web feed, and thereafter receives updated contents, every time updating takes place. Feed Readers may be online (like a webmail account) or offline. Recently a number of mobile readers have arrived to the market. An offline web feed is downloaded to the user's system. Feed readers are used in personalized home page services like iGoogle or My Yahoo or My MSN to put content such as news, weather and stock quotes appear on the user’s personal page. Content from other sites can also be added to that personalized page, again using feeds. Organizations can use a web feed server behind their firewall to distribute, manage and track the use of internal and external web feeds by users and groups. Other web-based tools are primarily dedicated to feed-reading only. One of the most popular web-based feed readers at this point is Bloglines, which is also free. Safari, Firefox, Internet Explorer 7.0, and many other web browsers allow receipts of feeds from the tool bar using Live Bookmarks, Favorites, and other techniques to integrate feed reading into a browser. Finally, there are desktop-based feed readers, e.g. Newsgator, FeedDemon, NetNewsWire, Outlook 2007 and Windows Live Mail.

Usually a web feed is made available by the same entity that created the content. Typically the feed comes from the same place as the website. However not all websites provide a feed. Sometimes third parties will read the website and create a feed for it by scraping it. A web search for 'screen scraping' or 'web scraping' finds tools that offer to perform this task. Scraping is controversial since it distributes the content in a manner that was not chosen by the content owner.

A web feed is a document (often XML-based) which contains content items with web links to longer versions. News websites and blogs are common sources for web feeds, but feeds are also used to deliver structured information ranging from weather data to "top ten" lists of hit tunes to search results. The two main web feed formats are RSS and Atom.

"Publishing a feed" and "syndication" are two of the more common terms used to describe making available a feed for an information source, such as a blog. Like syndicated print newspaper features or broadcast programs, web feed contents may be shared and republished by other websites. (For that reason, one popular definition of RSS is Really Simple Syndication.)

More often, feeds are subscribed to directly by users with aggregators or feed readers, which combine the contents of multiple web feeds for display on a single screen or series of screens. Some modern web browsers incorporate aggregator features. Depending on the aggregator, users typically subscribe to a feed by manually entering the URL of a feed or clicking a link in a web browser.

Web feeds are designed to be machine-readable rather than human-readable, which tends to be a source of confusion when people first encounter web feeds. This means that web feeds can also be used to automatically transfer information from one website to another, without any human intervention.

• Atom (standard)
• RSS (file format)
• Web syndication
• feed: URI scheme
• Wikipedia:Syndication

• Mark Pilgrim (18 December 2002). What is RSS?.
• Dave Shea (19 May 2004). What is RSS/XML/Atom/Syndication?.