We have so many chat tools today. Maybe too many and they are not opent to each other. This video compare the most of them in angle of privacy and technical aspect. This video does not talk from the perspective of use. How easy it is to register and or to use and or how popular it is. But I recommend to see because we it is easy to understand and we can learn many things. If you use the best tool but your contact doesn’t have it it is  useless.

I even know Wickr and session chat messager.