A quick skim of the Multi-User Chat though... Firstly, it's 9 years old :/ why is everyone still not using it? Secondly, you can immediately tell it's ridiculously over-engineered.

  <field var='muc#roominfo_occupants' label='Number of occupants'>
    <value>3</value>
  </field>

Sorry, but you can't really look at that protocol and say it's not ugly and verbose beyond reason. The number of occupants in a room is surely used enough to deserve an encoding of less than 75 characters to specify a number.