As chairman of the RSS Advisory Board, I've been called into two discussions recently about where people should link when referring to RSS 2.0.
The board's web site moved off Harvard's server in January 2006 to our own domain, rssboard.org. We've published the RSS 2.0 specification since 2003 and the current version of the document will always have the permanent URL http://www.rssboard.org/rss-specification. Our transition from Harvard's server to our own was described here.
Contrary to some claims I've read, the specification does not include new RSS elements or attributes that differ from what the board published prior to the server move. The only changes we've made to the document were administrative ones described in an August 2006 proposal and vote.
We're a public group that operates under a charter and has members from Microsoft, Yahoo, Netscape, Six Apart, BlogLines and others in the RSS community. I was asked to join in 2004 by Winer, who resigned shortly thereafter. I recently began a new two-year term as chair.
The copy of the RSS 2.0 specification archived by Winer is a just an older version of the spec. The board has archived the same version along with all of the older specs, for historical purposes.
There's contention within the RSS community about our work, as there is with anything involving RSS and syndication. But we've been conservative in regard to the specification and all other matters related to the format. We're primarily a place where people can get help with the format and developers can promote new namespaces and other ways to improve interoperability. Anyone who has questions about what we do is invited to join us on the public mailing list RSS-Public.