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.

This package provides a C++ library for parsing, formatting, and validating international phone numbers.

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.

Plugin for libpurple to allow sending SMS using ModemManager.

This package provides a fork of libsignal-protocol-c, used by Dino to provide OMEMO support.

Toxic is a console-based instant messaging client, using c-toxcore and ncurses. It provides audio calls, sound and desktop notifications, and Python scripting support.

This package shows CAPTCHA without running proprietary code.

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.

This package provides Python bindings to Zulip's API.

pn provides a command line tool that allows users to operate on phone numbers (get validity information, reformat them, or extract numbers from a text snippet), using libphonenumber.

Dino is a chat client for the desktop. It focuses on providing a minimal yet reliable Jabber/XMPP experience and having encryption enabled by default.

Psi+ is a spin-off of Psi XMPP client. It is a powerful XMPP client designed for experienced users.

This module implements support for a Encrypted Push Notifications, a custom extension to XEP-0357: Push Notifications.

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

OTR allows you to have private conversations over instant messaging by providing: (1) Encryption: No one else can read your instant messages. (2) Authentication: You are assured the correspondent is who you think it is. (3) Deniability: The messages you send do not have digital signatures that are checkable by a third party. Anyone can forge messages after a conversation to make them look like they came from you. However, during a conversation, your correspondent is assured the messages he sees are authentic and unmodified. (4) Perfect forward secrecy: If you lose control of your private keys, no previous conversation is compromised.

uTox is a lightweight Tox client. Tox is a distributed and secure instant messenger with audio and video chat capabilities.

ngIRCd is a lightweight Internet Relay Chat (IRC) server for small or private networks. It is easy to configure, can cope with dynamic IP addresses, and supports IPv6, SSL-protected connections, as well as PAM for authentication.

This package provides account management tools for Discord.

weechat-wee-slack is a WeeChat native client for Slack. It provides supplemental features only available in the web/mobile clients such as synchronizing read markers, typing notification, threads (and more)! It connects via the Slack API, and maintains a persistent websocket for notification of events.

This package provides python-pypresence, a Discord RPC client written in Python.

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.

Mcabber is a small XMPP (Jabber) console client, which includes features such as SASL and TLS support, Multi-User Chat (MUC) support, logging, command-completion, OpenPGP encryption, Off-the-Record Messaging (OTR) support, and more.

senpai is an IRC client that works best with bouncers.

Purple-lurch plugin adds end-to-end encryption support through the Double Ratchet (Axolotl) algorithm, to libpurple applications using XMPP,through its standard XEP-0384: OMEMO Encryption. It provides confidentiality, (weak) forward secrecy, break-in recovery, authentication, integrity, deniability, and asynchronicity.