How github "web push notifications" works?

Question

It seems that github uses a polling server for real time notifications (live.github.com) on its web interface.

It seems like the technology is not Websocket based neither XHR-polling.

How is it developed ?

Answer 1

It seems they use HTML5 Server-Sent Events.

I found it after a while by looking at the request to live.github.com that accepts "text/event-stream"