Other RDF RSS modules https://web.archive.org/web/20071201195657/http://web.resource.org/rss/1.0/modules/proposed.html
Raw Voice https://web.archive.org/web/20170331023439/http://www.rawvoice.com/services/tools-and-resources/rawvoice-rss-2-0-module-xmlns-namespace-rss2/
Comment API https://web.archive.org/web/20081004031716/http://wellformedweb.org/story/9
Comment Feed http://sellsbrothers.com/12548
Atom threads https://web.archive.org/web/20081115230920/http://www.snellspace.com/wp/?p=194