As a growing number of Rich Site Summary (RSS) feeds come online, they are becoming a useful tool for businesses looking to keep people informed.
Maybe you run a building supply business — why not incorporate a construction industry news feed into your Web site? Or are you an auto parts
supplier? Not only would an auto industry news feed be handy, but if most of your business is with a single client, say GM, plugging in to the GM news feed could be extremely useful.
Conversely, for those with the resources, an outgoing RSS feed can keep large customers and suppliers up to date on your own company news, pricing changes, inventory list updates and other oft-changing information.
RSS, an XML format originally designed to list the changing contents of a news Web site, was originally released by Netscape in 1997. It allowed users to customize their personal Netscape Web page and create content indices inside the Netscape browser. Abandoned by Netscape, the format lived on through a grassroots content syndication movement and has evolved through several versions. Today, RSS is widely used by news Web sites and Weblog authors.
The major attraction of RSS for Web developers is its simplicity. (In fact, RSS is often known by an alternative name, Really Simple Syndication.) An RSS file can be created from scratch using nothing more than a simple text editor and sample file as a template, posted to a Web server as though it were a Web page, and retrieved and read by a wide variety of applications. Additionally, numerous content management tools now create RSS files automatically and applications called headline readers enable users to view the contents.
A single RSS file, commonly known as a feed, consists of two major types of elements:
- a channel element, which describes the feed as a whole; and
- one or more item elements, which provide a summary of new content on the Web site.
The channel element describes the Web site title and base URL. Each item element contains an item title, URL, and a short description. Optional elements in an RSS file include a channel image and a form submission description.
Though originally designed for news content, and currently widely used by the news media, the most common use of RSS is to list Weblog contents.
An RSS file will typically display the most recent content of a Web site, usually 10 items or so, updated whenever a new item is added. RSS files are therefore read on a regular basis by software applications — known as harvesters or aggregators — that can scan for new entries and retrieve the data. An aggregator will check a large number of individual RSS files, returning to a given site once an hour or so. When new material is published to a news site or Weblog, it is very quickly picked up and distributed.
Because RSS files are structured data, and because they are updated so frequently, they support content syndication much more easily than a Web page. Popular aggregators, such as Blogdex, Daypop, Popdex, Technorati, Blogstreet and Feedster, are able to represent new content in a more user-friendly format than a regular search engine, including Yahoo! or Google. Because Weblog entries and news stories link to each other, these aggregators can quickly find the most popular new items.
Though most users employ RSS by turning to an aggregator Web site, many others use applications known as headline readers. A headline reader performs the same function as an aggregator, but is a stand-alone application that usually resides on the user’s own computer (though some, such as Bloglines, are stand-alone Web sites).
For users, the most commonly expressed benefit is convenience. RSS headline readers automatically flag new items, so one need not search through a number of Web sites looking for new content. Additionally, content is displayed first as a summary description, allowing users to browse quickly through numerous items. RSS readers also provide users with more choice and control because they can determine whether or not to subscribe to a given feed.
To be sure, RSS will evolve rapidly over the next few years. It’s poised to be exposed to a great deal of rhetoric, and is on the verge of being widely commercialized, with the inevitable cycle of hype and disappointment that will follow. That said, RSS is a technology with a strong future because of its simplicity, flexibility and utility. Although RSS is not the semantic Web originally dreamed of in the laboratory, with finely grained and standardized element descriptions and canonical vocabularies, it is a technology that has proven itself, and evolved roughshod, though the much grittier practice of grassroots development. There is, I think, a lesson in that.
Stephen Downes is senior research officer for the Institute for Information Technology, National Research Council, Canada. Downes specializes in research in online learning, online communities, and knowledge management. He also publishes a daily newsletter (OLDaily) about online learning. He can be contacted at firstname.lastname@example.org.
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