Aggregators

Aggregator (also called Feed Reader) refers to software, either on a client machine or as a web application, that brings together in a single location various items of web content for viewing and downloading. Aggregators inform users who have “subscribed” to a web source if there has been a change of content, and updates or downloads new content in accordance with used instruction. Examples of aggregators in use include blogs, podcasts and headlines information.

Aggregators relieve users of having to check in periodically with websites being monitored or followed, to see if anything new has taken place. Such “personal aggregators” are a common feature of browsers, email programs and portal sites like Yahoo, Google and MSN. Planet sites (named after the “Planet” aggregator) permit online communities to deposit blog updates in a common location. Formats normally used for the content of syndicated information are RSS, RDF/XML and Atom.

Media aggregators (called “Podcatchers”) handle subscriptions to audio and visual content feeds that can automatically update an ipod or similar media player.