River4 is the next in a series of river-of-news aggregators I've done, dating back to my.userland.com in 1999.
All data is stored on Amazon S3.
It's open source, GPL license.
It reads all kinds of feeds, all flavors of RSS, Atom, RDF.
It has almost no user interface. It reads a set of subscription lists, in a standard format, and monitors all the feeds in all the lists. When one updates, it adds an item to the output river, which is a JSON file, the perfect format for news applications.
Here's an example of a site that uses the output of the River4 engine.
It's my first river that runs on Linux. It runs everywhere Node.js runs, which is basically operating system out there. It's the hottest server platform, and now it has the best RSS software.
River4 very low cost to run, you can run the aggregator on Heroku for $0. Amazingly.
I'm doing a lot of development with tools that produce feeds. In order to innovate, I need to be able to add features on the aggregator side to match the ones in the feeds. This allows me to move quickly, much more quickly than I could if I didn't have a great aggregator that I can easily update. This is the model I used to develop RSS in the first place.
Every news organization, or company with a community should be running a river. By dramatically lowering the cost, and making it available on all operating systems, it gets much easier to run your own.
my.userland.com -- came out in 1999, alongside my.netscape.com. They were the first RSS reader sites. Netscape's was magazine-style, ours was a river.
Radio UserLand -- in 2002, an integrated blogging tool and RSS aggregator. This was the central product in the RSS bootstrap. It was the first to read and write OPML subscription lists. The New York Times feeds were shipped with Radio UserLand. This is where the market boomed.
River2 -- A complete rewrite of the RSS aggregator, in Frontier. All the previous rivers were Frontier apps, as was River3.
River3 -- Another rewrite. This time faceless. Ran out of a Dropbox folder.
Here's the GitHub repository. In the readme you'll see instructions on how to set up and install River4 on a Node.js system.