localoutline

A new category
  Every once in a while a new category of software catches on. It may borrow features from previous categories, but in some way, it represents a new activity with a computer. Often the category existed for a while, even years, before it caught on. That was true of weblogs, and now it's true of another category, news aggregators.
  We did our first aggregator in 1999, a centralized application called My.UserLand. It was a contemporary of My.Netscape, which took the same information, in a format called RSS, and displayed it in a series of boxes, one for each source. Our software presented a stream of new items, the newest items at the top of the stream (most visible) and the older items towards the bottom. In Web terminology this form of presentation is called reverse-chronological.
  Today, our aggregator is decentralized, it's a key part of our Radio UserLand software. We have competition, our software is not the only desktop news aggregator on the market. There's a lot more to say about the category, but first a definition.
What is a News Aggregator?
  A news aggregator is "software that periodically reads a set of news sources, in one of several XML-based formats, finds the new bits, and displays them in reverse-chronological order on a single page."
How does a news aggregator work?
  Every hour the aggregator reads the "feeds" you're subscribed to, as few as a half-dozen, or as many as you like. When you see an item that you want to amplify with your own comments, or pass on to others in your organization or interest group, with a couple of clicks you can "route" it to the home page of your weblog. Aggregators and weblog software are flip-sides of the same idea. Weblogs are for writing, aggregators for reading, and at the intersection is routing.
Amateurs and pros
  I'm subscribed to quite a few sources, and the range of sources is significant. Consider that I get news from the New York Times, the BBC, and from weblogs like Sam Ruby (an expert programmer), Jon Udell (InfoWorld columnist), John Robb (he works with me at UserLand), Mike Chambers (works for Macromedia, writes about Flash), The Shifted Librarian, Ernie the Attorney, analyst Kevin Werbach, Ed Cone (North Carolina columnist), book author Christian Crumlish, my own weblog (Scripting News). I also subscribe to News.Com, The Motley Fool, The Register, Doc Searls, a local newspaper in South Carolina (Go Upstate), O'Reilly's Safari service and Patrick Logan (a developer). I am currently subscribed to 73 feeds, some people I know are subscribed to as many as 300!
  The key point is that I don't have to visit each of these sites to find out what's new. My computer, running aggregator software, does it for me, every hour, automatically. The information is formatted in XML, but I am barely aware of that, as with all compelling apps, the technical details are tucked out of the way. Like all open formats, it's easy to figure out what's going on. Here's an example of the XML behind news aggregators.
  Not only am I getting news from professional news organizations, but I am also hearing from people and non-news organizations who make a difference to me. Rarely an hour goes by without something interesting happening, my mind is stimulated, I get new ideas, and of course I share them. It's all about choice, customization, and communication. No one has the same virtual newspaper as mine, and mine is changing all the time.
  Over the last few months it's been interesting to watch many of the smart people in weblog-land discover the convenience and power of news aggregators. In many ways it feels like aggregators are where weblogs were a couple of years ago, just about to be discovered by a much larger group of people.
  Dave Winer
See also
  Jon Udell's BYTE column on personal RSS aggregators.
  Screen shot of the aggregator built into Radio UserLand.