Description

Jabber was the first bigger chat-service, hosted at tchncs.de. The focus has since shifted towards the Matrix Server.
tchncs.de forces TLS encryption for clients and servers, so it is nearly impossible to accidentally chat unencryptet. Your password will be stored securely hashed.

What is Jabber?

Well, rough explained it provides similar functionallity like MSN or ICQ.
Jabber is based on the XMPP chatprotocol, which was also used by Google and Facebook for a longer time for offering chat to the users. You have the choice between thousands of servers and all can talk together.