Atom
The Atom Syndication Format is an XML-based file format intended to allow lists of information, known as "feeds", to be synchronised between publishers and consumers. Feeds are composed of a number of items, known as "entries", each with an extensible set of attached metadata. For example, each entry has a title.
The primary use case that Atom addresses is for syndicating Web content such as Weblogs and news headlines to other Web sites and directly to consumers. However, nothing precludes it from being used for other purposes and types of content.