Creating an Atom feed in PHP

Creating an Atom feed in PHP: "Atom is an XML specification that identifies information contained in a Web site. Using Atom, Web developers produce feeds that enable other Web developers (or consumers who use feed readers) to quickly locate and view information of interest on a remote site. Think of it as a Web site's index, available to anyone who wants it. Using PHP, a popular language of choice for most host providers, a Web developer can easily produce an Atom feed that can then be made available to the various feed readers and other Web developers. The ultimate result is a state-of-the-art information solution that enables the Web content to reach a much wider audience."