Atom is an XML format utilized to get users informed about new content on a Website. Users can subscribe to an Atom feed, view new content from websites in abbreviated format with a corresponding Atom feed reader, and share it. Content providers can provide Atom feeds to inform users and search engines about new content. Atom feeds are a type of content syndication, in other words, content distributed and shared in a uniform format. They are specifically well-suited for webblogs.
The Atom feed is the competing format for the RSS feed. Both feeds are based on XML but differ in various respects. Atom, similar to RSS provides different data in the form of XML tags: content is structured and made readable in abbreviated form. Both browsers and special feed readers can read and display the XML format albeit in a different layout.
The original function of Atom feeds is to provide website users with a consistent format that allows them to be quickly and easily informed about news on different websites. Users only need to subscribe to an Atom feed, and can then use various Feed readers or their browser. The atom format as such has the advantage that different data types can be syndicated which is impossible with an RSS feed.
In addition, Atom is intended to provide a uniform format that is freely accessible. Development of the RSS format has now been discontinued and as a proprietary software it is subject to various licensing conditions, which is a major disadvantage compared to the atom format.
<?xml version="1.0" encoding="utf-8"?> <feed xmlns="http://www.w3.org/2005/Atom"> <title>Sample Feed</title> <link href="http://www.sample.org/"/> <updated>2005-12-13T17:30:01Z</updated> <author> <name>Joe Smith</name> </author> <id>urn:uuid:60a76c80-d399-11d9-b93C-0003939e0af6</id> <entry> <title>Atom Feed Sample</title> <link href="http://sample.org/2005/12/13/atom05"/> <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id> <updated>2005-12-13T17:30:01Z</updated> <summary>Text line</summary> </entry> </feed>
The possible elements and rules for the structure can be found in the IETF standard. There are also suitable editors that simplify the creation of atom feeds. Some Content Management Systems provide such functionalities as well.
Similar to RSS feeds, Atom feeds have a reputation for generating duplicate content. Content syndication using feeds should therefore always be accompanied by appropriate measures to avoid negative effects. Outgoing links should be tagged with rel="nofollow". Search engines will get an indication about new content on a website, but feeds are often abused as spam. Such feeds should therefore be utilized with caution. Feed editor are beneficial in this context, since you can control the data transmissions yourself.