In computing, a feed aggregator, also known as a feed reader or simply as an aggregator, is
client software or a Web application which
aggregates syndicated web content such as news headlines, blogs, podcasts, and vlogs in a single
location for easy viewing.
Functions
Aggregators reduce the time and effort needed to regularly check websites for updates, creating a unique information space or
"personal newspaper." Once subscribed to a feed, an aggregator is able to check for new content at user-determined intervals and
retrieve the update. The content is sometimes described as being "pulled" to the
subscriber, as opposed to "pushed" with email or
IM. Unlike recipients of some "pushed" information, the aggregator user can easily
unsubscribe from a feed.
Aggregator features are frequently built into portal sites (such as My Yahoo! and
iGoogle), modern Web browsers and email programs.
The aggregator provides a consolidated view of the content in a single browser display or desktop application. Such
applications are also referred to as RSS readers, feed readers, feed
aggregators, news readers or search aggregators. Aggregators with
podcasting capabilites can automatically download media files, such as MP3 recordings. In some
cases, these can be automatically loaded onto portable media players (like
iPods) when they are connected to the PC.
Recently, so-called RSS-narrators have appeared, which not only aggregate text-only news feeds, but also convert them
into audio recordings for offline listening.
The syndicated content an aggregator will retrieve and interpret is usually supplied in the form of RSS or other XML-formatted data, such as RDF/XML or Atom.
Varieties
The variety of software applications and components that are available to collect, format, translate, and republish
XML feeds is a testament to the flexibility of the format and has shown the usefulness of
presentation-independent data.
Web-based
Web-based aggregators are applications that reside on remote servers and are typically available as Web applications such as Google Reader or Bloglines. Because the application is available via the Web, it can be
accessed anywhere by a user with an Internet connection.
More advanced methods of aggregating feeds are provided via AJAX coding techniques
and XML components known as Web widgets. Ranging from
full-fledged applications to small fragments of code that can be integrated into larger programs, they allow users to aggregate
OPML files, email services, documents, or feeds into a single interface. Many customizable
homepage/portal implementations such as iGoogle, Live.com,
My Yahoo!, and Pageflakes provide such functionality.
In addition to personal aggregators, planet sites are used by online communities to aggregate community blogs in a
centralised location. Such sites are named after the Planet aggregator, an application
designed for this purpose.
Client software
Client software aggregators are installed applications designed to collect Web feed subscriptions and group them together
using a user-friendly interface. The graphical user interface of such
applications often closely resembles that of popular e-mail clients, using a three-panel
composition in which subscriptions are grouped in a frame on the left, and individual entries are browsed, selected, and read in
frames on the right.
Software aggregators can also take the form of news tickers which scroll feeds like
ticker tape, alerters that display updates in windows as they are refreshed, or as smaller
components (sometimes called plugins or extensions), which can integrate feeds into the Operating
System or software applications such as a Web browser.
Client Libraries
Many programming languages have libraries that are able to download, process, generate and upload RSS feeds. Perl for example has several libraries in the XML::RSS name space of CPAN.
Media Aggregators
Media aggregators are sometimes referred to as "Podcatchers" due to the popularity of the term "podcast" used to refer to a web feed containing audio or video. Media aggregators refer to applications, client
software or Web based, which maintain subscriptions to feeds that contain audio or video media
enclosures. They can be used to automatically download media, playback the media within the application interface, or
synchronize media content with a portable media player.
Feed filtering
One of the problems with news aggregators is that the volume of articles can sometimes be overwhelming, especially when the
user has many Web feed subscriptions. As a solution, many feed readers allow users to tag
each feed with one or more keywords which can be used to sort and filter the available articles
into easily navigable categories.
See also
External links
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
