Plugin for libpurple to allow sending SMS using ModemManager.

LibGadu is library for handling Gadu-Gadu instant messenger protocol. The library is written in C and aims to be operating system and environment independent.

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

This package provides Ejabberd -- Robust, Ubiquitous and Massively Scalable Messaging Platform. It supports XMPP, MQTT and SIP protocols.

mtxclient is a C++ library that implements client API for the Matrix protocol. It is built on to of Boost.Asio.

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

This library implements OMEMO of XMPP (XEP-0384) in C.

Pidgin-OTR is a plugin that adds support for OTR to the Pidgin instant messaging client. OTR (Off-the-Record) Messaging 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.

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.

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.

C library implementation of the Tox encrypted messenger protocol.

Purple-Mattermost is a plug-in for Purple, the instant messaging library used by Pidgin and Bitlbee, among others, to access Mattermost servers.

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.

Profanity is a console based XMPP client written in C using ncurses and libmesode, inspired by Irssi.

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.

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.

Net::PSYC with support for TCP, UDP, Event.pm, IO::Select and Gtk2 event loops. This package includes 12 applications and additional scripts: psycion (a PSYC chat client), remotor (a control console for tor router) and many more.

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.

Poezio is a free console XMPP client (the protocol on which the Jabber IM network is built). Its goal is to let you connect very easily (no account creation needed) to the network and join various chatrooms, immediately. It tries to look like the most famous IRC clients (weechat, irssi, etc). Many commands are identical and you won't be lost if you already know these clients. Configuration can be made in a configuration file or directly from the client. You'll find the light, fast, geeky and anonymous spirit of IRC while using a powerful, standard and open protocol.

GNT is an ncurses toolkit for creating text-mode graphical user interfaces in a fast and easy way. It is based on GLib and ncurses.

GNU Freetalk is a command-line Jabber/XMPP chat client. It notably uses the Readline library to handle input, so it features convenient navigation of text as well as tab-completion of buddy names, commands and English words. It is also scriptable and extensible via Guile.

libsignal-protocol-c is an implementation of a ratcheting forward secrecy protocol that works in synchronous and asynchronous messaging environments. It can be used with messaging software to provide end-to-end encryption.

Mesecons is a mod for Luanti implementing various items related to digital circuitry, such as wires, buttons, lights and programmable controllers. Among other things, there are also pistons, solar panels, pressure plates and note blocks.

Mesecons has a similar goal to Redstone in Minecraft, but works in its own way, with different rules and mechanics.

Pipeworks is a mod for Luanti implementing 3D pipes and tubes for transporting liquids and items and some related devices. Pipes and tubes can go horizontally or vertically. Item tubes can also be used for sorting items and extracting items from chests or putting items in chests. Autocrafters can automatically follow craft recipes to make new items and can be fed by item tubes. Deployers can place items in the world as a player would. Node breakers simulate a player punching a node.