http://moq7aejnf4xk5k2bkaltli3ftkhusy2mbrd3pj23nrca343ku2mgk4yd.onion/guestbook?lang=ru
There are listener_add and listener_remove options. Before that a Liquidsoap was used. But it failed to play most of audio files for no known reason. Its logs said nothing on why it was constantly reloading a playlist. And, it is relatively heavy on CPU (23-25%) and memory (hmm, don't remember, but something like over 100MB), unlike Ezstream which constantly reports 0% CPU utilization and occupies just 9MB of RAM.