Whenever you talk about syndication, you have to deal with confusion regarding the multiple meanings of the term RSS.
RSS refers to the format Really Simple Syndication, also known as RSS 2.0.
RSS refers to the format RDF Site Summary, also known as RSS 1.0.
RSS refers collectively to all syndication feeds, whether they're in RSS 1.0, RSS 2.0 or Atom format.
I floated a proposal to the RSS-DEV Working Group last night to rename RSS 1.0 as RSS-RDF (RSS for the Resource Description Framework).
I'm asking for trouble by suggesting the idea, but as syndication has grown, RSS 2.0 appears to be eating RSS 1.0's lunch. According to the feed stats published on the syndication directory Syndic8, 76.3 percent of its RSS feeds are RSS 2.0 and 11.3 percent are RSS 1.0.
Here's their past Syndic8 percentages, using pages archived by the Internet Archive:
- February 2006: RSS 2.0 68.3%, RSS 1.0 17.6%
- March 2005: RSS 2.0 62.1%, RSS 1.0 16.5%
- December 2004: RSS 2.0 49.2%, RSS 1.0 20.6%
- April 2004: RSS 2.0 24.6%, RSS 1.0 47.3%
Those dates aren't necessarily correct, since they depend on how often Syndic8 runs statistics reports. But the trend is pretty clear.
We can debate the reasons why, but my guess is that RSS 2.0's higher version number is as much a factor as anything else. I expect that RSS 2.0 will continue to grow relative to RSS 1.0 because of Microsoft's choice to normalize to RSS 2.0 in Windows Vista and MSIE.
Each of the popular syndication formats has a strong selling point:
- Atom is an Internet standard that's more adaptable to uses outside site syndication
- RSS 1.0 builds on RDF
- RSS 2.0 is simple, loose and popular
Giving RSS 1.0 the name RSS-RDF makes its status as an RDF format more prominent and allows some elbow room to open up between two similarly named formats with a common origin.