The following is a chart accompanying an article published by Directions on Microsoft, an independent research firm focused exclusively on Microsoft strategy & technology. Each month we make one or more key articles available to non-subscribers.
This chart shows the various flavors of RSS in chronological order. The first format to be called RSS (version 0.9) was developed by Netscape to help third-party Web sites plug in to the My Netscape portal and was known as RDF Site Summary. (RDF, or the Resource Description Framework, is an XML format for describing relationships between Web entities.) This version of RSS eventually became RSS 1.0.
Meanwhile, Dave Winer, a Web logging ("blogging") pioneer, recognized that blogs and other sites needed a simple way to describe their content and inform interested readers of updates. So, at the same time that RDF proponents were establishing a working group to make improvements to the RDF-based version of RSS, Winer and others developed a simpler alternative dubbed "Really Simple Syndication." Winer's version eventually became RSS 2.0.
Because the two main branches (one leading to RSS 1.0, the other to RSS 2.0) were developed simultaneously and both used the name "RSS," the version numbers aren't sequential. Although Microsoft plans on supporting all of these RSS flavors in the final version of Longhorn (along with two versions of Atom—an alternate syndication format), not all will be supported in Beta 1, which is expected to be available in summer 2005.
