I am looking at it for the first time but the built in mqtt integration (which extends to browsers) [1] and support for live templates [2] is interesting. It is also interesting that the support for live templates and realtime client server integration predates phoenix liveviews by a long margin.

[1] http://docs.zotonic.com/en/latest/ref/modules/mod_mqtt.html#...

[2] http://docs.zotonic.com/en/latest/ref/scomps/scomp_live.html...