I used Emacs Lisp’s xml-parse-file to get the ParticipantJoinEvent and ParticipantLeftEvent entries from the BigBlueButton raw events.xml files for #EmacsConf so that I could calculate the max number of simultaneous users: 62 during EmacsConf (not including the people who were viewing the stream). Analysis and code at https://sachachua.com/blog/2023/12/emacsconf-backstage-figuring-out-our-maximum-number-of-simultaneous-bigbluebutton-users/