IM clients

Element is a free and open source, cross-platform and secure desktop instant messaging client of the Matrix network

Movim is a free and open source social and chat platform that acts as a web interface for the XMPP protocol

Retroshare is a free and open source, multi-platform platform for the confidential exchange of files and messages via an encrypted Friend-to-Friend network

Jami is a free and open source, cross-platform, privacy-oriented voice, video, chat, and conference platform

Jitsi Meet is a free and open source, multi-platform software for secure, simple, and scalable video conferences

qTox is a free and open source instant messaging client with support for text, voice, and video chats, using the encrypted Tox protocol

Gajim is a free and open source, multi-platform, easy-to-use, and full-featured XMPP client

HexChat – free and open source, cross-platform IRC client, forked from XChat

Dino – free and open source modern XMPP (jabber) chat client with support for end-to-end OMEMO and OpenPGP encryption

Psi+ – cross-platform powerful XMPP client, implementation of the Psi jabber client with newer features and faster bug fixes