Prosody

Prosody is a small and fast XMPP daemon written in Lua. You can install it like this:

sudo apt-get install prosody

Then edit the config /etc/prosody/prosody.cfg.lua to make sure you have BOSH support, group rosters and compression enabled, and you probably want self-registration off:

modules_enabled = {
  "compression";
  "bosh";
  "groups";
  ...
}

allow_registration = false;
bosh_ports = { 5280 };

...