This is a short demo (public chat) displaying apex comunication with node.js using websockets (socket.io library)...
The repo of this demo can be found on github
For start enter your chatname
To chat with some one send them your current url ( https://apex.oracle.com/pls/apex/f?p=101959:16
you can chat with your self, open new tab with the same url and enter your second chatname
The blog post for more technical detail can be found here
Also chat will ask you for grant notification
display, this means when chat demo tab in browser is not active it will display message when new message arrives.