An atom is a XML-standard, that allows platform independent exchange of information. It is seen as the new RSS, Really Simple Syndication, which is also part of the XML family and same as an atom commonly used by news websites and weblogs.
Atom was created by the main users of weblogs, to simplyfy the Really Simple Syndications. Due to the number of different RSS-formats, the need occured to combine all of them into one and add new elements to it, matching the blogger’s needs. The main suporters are organised in the industrial union Atom Enabled Alliance.
The latest version of the Atom Syndication Format is the IETF-design from the 11th August 2005, which was granted from UESP in August 2005 as a Proposed Standard and which was published as RTF 4287 in decemeber 2005. Since then, atom is an official internet standart and most big feed-supplier are working on supporting it. The MIME-Type of atom is application/atom xml.