Robust, Ubiquitous and Massively Scalable Messaging Platform (XMPP, MQTT, SIP Server)

Conversations is an open source XMPP/Jabber client for Android

Jitsi is an audio/video and chat communicator that supports protocols such as SIP, XMPP/Jabber, IRC and many other useful features.

Web-based XMPP/Jabber chat client written in JavaScript

An XMPP server licensed under the Open Source Apache License.

A modular and portable open source XMPP client library written in Java for Android and Java (SE) VMs

Modern XMPP ("Jabber") Chat Client using GTK+/Vala

MongooseIM is Erlang Solutions' robust, scalable and efficient XMPP server, aimed at large installations. Specifically designed for enterprise purposes, it is fault-tolerant and can utilise the resources of multiple clustered machines.

💬 Instant messaging server for the Extensible Messaging and Presence Protocol (XMPP).

Ncurses based XMPP client

An IRC to other chat networks gateway 🐝

Cross-platform real-time collaboration client optimized for business and organizations.

Go XMPP Library (From Yasuhiro Matsumoto and based on the code from Russ Cox)

Monal for XMPP (iOS and macOS)

Miranda NG: Next Generation of Miranda IM

JabberD XMPP Server

(M) Highly optimized, extremely modular and very flexible XMPP/Jabber server

Adium is an open source and free instant messaging application for macOS that can connect to XMPP (Jabber), IRC and more.

XEP-0384: OMEMO Encryption for libpurple.

(M) XMPP client for macOS based on TigaseSwift XMPP library