Element.io - Secure messaging app with strong end-to-end encryption, advanced group chat privacy settings, secure video calls for teams, encrypted communication using Matrix open network. Riot.im is now Element.

Chatib - Chatib is an online chat room where you can meet and chat with new people, make them friends, or even data them online.

Chatingar - Chatingar.com is free chat rooms for online chat and connections worldwide. Find your perfect match and chat instantly!

Otr.to - A secure peer-to-peer chat in your web browser.

ChatSecure - ChatSecure is a free and open source messaging app that features OTR encryption over XMPP.

Kandan - Open Source private chat server. Your own private Chat server in minutes, plus additional features.