Really Simple Syndication or RSS is an aggregated web platform applied across the virtual interface of the internet. RSS feed reader or aggregator web tool is used to check RSS enabled WebPages to find and display the updated contents from the feeds.
RSS enabled web pages also known as RSS documents are described by a set of tags like <rss> or <rdf:RDF> tag. Multiple RSS standards are also there but they differ from file to file. RSS standards are not compatible in the standard parameters of content syndication since they are developed by different people. Atom format is helpful to overcome this situation.
Atom is an XML-based document format and HTTP-based protocol designed for the Web content syndication such as Weblogs, Web sites with news headlines or other user enabled sites. It is similar to the various versions of RSS, but aims to be more flexible. Critics would argue that it has merely created additional confusion.
Atom implementers urged to wait until the spec is finished before deploying it, so that interoperability problems (http://diveintomark.org/archives/2004/02/04/incompatible-rss) are minimized. Atom Project produces the “Atom Publishing Protocol” with a similar aim of improving and replacing existing publishing mechanisms, such as the Blogger API and Live Journal XML-RPC Client/Server Protocol. Atom was previously known as “Echo”.
Gmail provides an atom feed of a user’s inbox.
Feed Readers or News aggregators in general are the extensions of web browsers, email programs, or desktop programs. Some browsers like Mozilla Firefox (via “live bookmarks”) have native in built support of RSS and/or Atom, Opera has it via an RSS browser, Safari also has RSS support.
Now Web-based feed readers and News aggregators are also available. For example My Yahoo – Yahoo’s user-customizable Web page, Waggr and Bloglines. Since they are web based, they can be accessed from anywhere via a web browser.
RSS Popper (http://www.rsspopper.com/) is a free RSS/RDF/Atom news aggregator Add-In for MS-Outlook.
BlogExpress is a full-featured .NET application for content syndication. BlogExpress supports all RSS versions and Atom.