Loudmouth is a lightweight and easy-to-use C library for programming with the XMPP (formerly known as Jabber) protocol. It is designed to be easy to get started with and yet extensible to let you do anything the XMPP protocol allows.

MQTT and MQTT-SN are lightweight publish/subscribe messaging transports for TCP/IP and connection-less protocols (such as UDP). The Eclipse Paho project provides client side implementations of MQTT and MQTT-SN in a variety of programming languages. This package is for the Python implementation of an MQTT version client class.

qTox is a Tox client that follows the Tox design guidelines. It provides an easy to use application that allows you to connect with friends and family without anyone else listening in.

This package provides group handling for mod_invites_register

This module implements XEP-0198: when supported by both the client and server, it can allow clients to resume a disconnected session, and prevent message loss.

BitlBee brings IM (instant messaging) to IRC clients, for people who have an IRC client running all the time and don't want to run an additional IM client. BitlBee currently supports XMPP/Jabber (including Google Talk), MSN Messenger, Yahoo! Messenger, AIM and ICQ, and the Twitter microblogging network (plus all other Twitter API compatible services like identi.ca and status.net).

This module implements XEP-0363: it allows clients to upload files over HTTP.

This package provides Eclipse Mosquitto, a message broker that implements the MQTT protocol versions 5.0, 3.1.1 and 3.1. Mosquitto is lightweight and is suitable for use on all devices from low power single board computers to full servers.

The MQTT protocol provides a lightweight method of carrying out messaging using a publish/subscribe model. This makes it suitable for Internet of Things messaging such as with low power sensors or mobile devices such as phones, embedded computers or microcontrollers.

jj is a simple file-system-based Jabber client, inspired by ii IRC client. Interaction with jj is done by writing and reading files from the server directory which jj creates. It is perfect for bots and notifications.

Libircclient is a library which implements the client IRC protocol. It is designed to be small, fast, portable and compatible with the RFC standards as well as non-standard but popular features. It can be used for building the IRC clients and bots.

This module adds an API for sending and receiving XMPP stanzas.

libcmatrix is a library for writing Matrix clients in C. It handles transparently end-to-end encryption (E2EE), and stores messages/events in a local database.

Official fork of the C library implementation of the Tox encrypted messenger protocol.

Nheko want to provide a native desktop app for the Matrix protocol that feels more like a mainstream chat app and less like an IRC client.

Many matrix features are supported, including user registration, rooms, typing notification, emojis, E2E encryption, and voip calls.

This module implements support for a Tigase XMPP extension, Priority of notifications. It is a custom extension to XEP-0357: Push Notifications.

ZNC is an IRC network bouncer or BNC. It can detach the client from the actual IRC server, and also from selected channels. Multiple clients from different locations can connect to a single ZNC account simultaneously and therefore appear under the same nickname on IRC.

Relays messages between different channels from various messaging networks and protocols. So far it supports mattermost, IRC, gitter, xmpp, slack, discord, telegram, rocketchat, twitch, ssh-chat, zulip, whatsapp, keybase, matrix, microsoft teams, nextcloud, mumble, vk and more with REST API. Mattermost is not required.

WhatsCLI is a command-line interface for WhatsApp that connects through the Web App API without requiring a browser. It provides a terminal-based user interface built with tview, featuring:

• Sending and receiving WhatsApp messages in a terminal

• QR code setup for simple authentication

• Downloading and opening image, video, audio, and document attachments

• Sending images, video, audio, and document attachments

• Basic group management capabilities

• Desktop notifications support

• Color customization options

This module adds the ability to set vCard for MUC rooms. One of the most common use cases is to define avatars for MUC rooms.

This package provides Zulip's Bot framework.

twtxt is a decentralised, minimalist microblogging service for hackers.

So you want to get some thoughts out on the internet in a convenient and slick way while also following the gibberish of others? Instead of signing up at a closed and/or regulated microblogging platform, getting your status updates out with twtxt is as easy as putting them in a publicly accessible text file. The URL pointing to this file is your identity, your account. twtxt then tracks these text files, like a feedreader, and builds your unique timeline out of them, depending on which files you track. The format is simple, human readable, and integrates well with UNIX command line utilities.

libqmatrixclient is a Qt library to write clients for the Matrix instant messaging protocol. Quaternion is the reference client implementation. Quaternion and libqmatrixclient together form the QMatrixClient project.

Gajim aims to be an easy to use and fully-featured XMPP chat client. It is extensible via plugins, supports end-to-end encryption (OMEMO and OpenPGP) and available in 29 languages.

Quaternion is a Qt desktop client for the Matrix instant messaging protocol. It uses libqmatrixclient and is its reference client implementation.