http://6pb473duz5o6kdvedrvplpyce33ezwjxkehbwtagytxe6yqal4xe44yd.onion/articles/xmpp.html
Out of the 380 keyword-selected servers I analyzed, I could only rate 89. In my analysis, I came upon around 24 private (members only) servers, which I chose not to rate because of their private statuses.