As you have mentioned many chat system... We thought about adding chat module to our open source trello clone called Restyaboard http://restya.com/board/ http:/

As you have mentioned many chat system... We thought about adding chat module to our open source trello clone called Restyaboard http://restya.com/board/ http://restya.com/board/ Do you think if this will not be useful addition? Or what chat system among above will be useful to integrate?