my favourite RSS reader: SAGE within Firefox

I remember, I haven't told you yet, how I read my RSS subscriptions. I am using SAGE.
It has an XML based exchange format called OPML, which is actually just a format for listing outlines of books, articles, whatever, and apart from the SAGE aspect: I love to edit OPML in emacs's nxml mode. Let me know, if you are interested in the RELAX NG grammar, that I created for that purpose.
The major advantage of being integrated into a web browser is, that the RSS subscriptions come as a standard live bookmark tree and URLs are opened nicely in web browser tabs. Of course, all the articles you already visited are displayed no longer in bold, so you won't revisit them unknowingly.