What technologies to choose for creating a user support chat?

Question

Programming

There is a need to create your own chat like siteheart.com, but, as usual, with blackjack and other joys of life. There was a question about the choice of technology, so far we are leaning towards TornadIO2, Socket.IO and MongoDB. But since none of the team has worked with these technologies, the question of choice is open. The main requirement for the chat is the ability to fully customize the appearance, so there are no special requirements for the server part, even in terms of load.

Answer 1

and just a sheaf on ajax does not approach?