Irssi is an IRC client program for Linux, FreeBSD, macOS and Microsoft Windows. It was originally written by Timo Sirainen, and released under the terms of the GNU General Public License in January 1999.
ICQ is a cross-platform instant messaging and VoIP client. The name ICQ derives from the English phrase "I Seek You". Originally developed by the Israeli company Mirabilis in 1996, the client was bought by AOL in 1998, and then by Mail.Ru Group in 2010.
Pidgin is a free and open-source multi-platform instant messaging client, based on a library named libpurple that has support for many instant messaging protocols, allowing the user to simultaneously log into various services from a single application, with a single interface for both the popular and obsolete protocols, thus avoiding the hassle of having to deal with a new bloated, unaudited, closed-source, and different piece of software for each device and protocol.
Kopete is a multi-protocol, free software instant messaging client released as part of the KDE Software Compilation. Although it can run in numerous environments, it was designed for and integrates with the KDE Plasma Workspaces. Kopete was started because ICQ blocked Licq from their network in 2001. According to the original author, Duncan Mac-Vicar Prett, the name comes from the Chilean Spanish word copete, meaning "a drink with your friends". Kopete has been nominated for multiple awards. The designated successor is KDE Telepathy from the KDE RTCC Initiative.
Centericq is a text mode menu- and window-driven instant messaging interface that supports the ICQ, Yahoo!, AIM, MSN, IRC, XMPP, LiveJournal, and Gadu-Gadu protocols. It allows you to send, receive, and forward messages, URLs, SMSes, contacts, and email express messages, and it has many other useful features. Known to work in Linux, FreeBSD, NetBSD, OpenBSD, Solaris, Windows and macOS/Darwin Operating Systems.
cURL is a computer software project providing a library (libcurl) and command-line tool (curl) for transferring data using various protocols. It was first released in 1997. The name stands for "Client URL". The original author and lead developer is the Swedish developer Daniel Stenberg.
OpenVPN is an open-source commercial software that implements virtual private network (VPN) techniques to create secure point-to-point or site-to-site connections in routed or bridged configurations and remote access facilities. It uses a custom security protocol that utilizes SSL/TLS for key exchange. It is capable of traversing network address translators (NATs) and firewalls. It was written by James Yonan and is published under the GNU General Public License (GPL).
BitlBee is a cross-platform IRC instant messaging gateway, licensed under the terms of the GNU General Public License.
Gajim is an instant messaging client for the XMPP protocol which uses the GTK+ toolkit. The name Gajim is a recursive acronym for Gajim's a jabber instant messenger. Gajim runs on Linux, BSD and Microsoft Windows. Released under the GNU General Public License, Gajim is free software. A 2009 round-up of similar software on Tom's Hardware found version 0.12.1 "the lightest and fastest jabber IM client".
The following tables compare general and technical information between a number of IRC client programs which have been discussed in independent published literature.
MCabber is a free software client for the instant messaging protocol XMPP with a text user interface based on ncurses. It runs on a range of platforms, including Linux, BSD, and Mac OS X. As free software it is freely available – including the source code – under the terms of the GNU General Public License (GPL). MCabber is the successor of Alejandro Jimenez Macias' earlier Cabber that has had releases from 2002 to 2004. In 2005 it has been forked off the last version of Cabber (0.5.0).
This is a comparison of notable free and open-source configuration management software, suitable for tasks like server configuration, orchestration and infrastructure as code typically performed by a system administrator.
Linphone is a free voice over IP softphone, SIP client and service. It may be used for audio and video direct calls and calls through any VoIP softswitch or IP-PBX. Also Linphone provides the possibility to exchange instant messages. It has a simple multilanguage interface based on GTK+ for GUI and can also be run as a console-mode application on Linux.
WeeChat is a free and open-source Internet Relay Chat client, which is designed to be light and fast. It is released under the terms of the GNU General Public License 3 and has been developed since 2003.
CommuniGate Pro (CGP) is a scalable carrier grade email server, unified communications server, true FMC solutions as well as development platform all integrated into one.
Tkabber is a GPL instant messaging client for the XMPP protocol which uses the Tk toolkit for the GUI. It runs on anything to which Tcl/Tk is ported: almost any X-based system, Microsoft Windows, and Mac OS X.
Ayttm is a multi-protocol instant messaging client. It is the heir of the EveryBuddy project.
Coccinella is a free and open-source cross-platform client for the XMPP/Jabber-instant messaging-protocol.
OpenConnect is an open-source software application for connecting to virtual private networks (VPN), which implement secure point-to-point connections.
Spark is an open-source instant messaging program that allows users to communicate via text in real time. It can be integrated with the Openfire server to provide additional features, such as controlling various parts of Spark functionality from a central management console, or integrating with a customer support service Fastpath, allowing Spark users to log into queues, accept and forward support requests, use canned responses. Being a cross-platform application, it can be run on various systems. Installers for Windows, macOS and Linux are available on the official website.
