Messenger was an instant messaging and presence system developed by Microsoft in 1999 for use with its MSN Messenger software. It was used by instant messaging clients including Windows 8, Windows Live Messenger, Microsoft Messenger for Mac, Outlook.com and Xbox Live. Third-party clients also connected to the service. It communicated using the Microsoft Notification Protocol, a proprietary instant messaging protocol. The service allowed anyone with a Microsoft account to sign in and communicate in real time with other people who were signed in as well.
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 in to various services from a single application, with a single interface for both popular and obsolete protocols, thus avoiding the hassle of having to deal with a new software for each device and protocol.
Extensible Messaging and Presence Protocol is an open communication protocol designed for instant messaging (IM), presence information, and contact list maintenance. Based on XML, it enables the near-real-time exchange of structured data between two or more network entities. Designed to be extensible, the protocol offers a multitude of applications beyond traditional IM in the broader realm of message-oriented middleware, including signalling for VoIP, video, file transfer, gaming and other uses.
climm is a free CLI-based instant messaging client that runs on a wide variety of platforms, including AmigaOS, BeOS, Windows, OS X, NetBSD/OpenBSD/FreeBSD, Linux, Solaris, HP-UX, and AIX.
iChat is a discontinued instant messaging software application developed by Apple Inc. for use on its Mac OS X operating system. It supported instant text messaging over XMPP/Jingle or OSCAR (AIM) protocol, audio and video calling, and screen-sharing capabilities. It also allowed for local network discussion with users discovered through Bonjour protocols.
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.
Message-oriented middleware (MOM) is software or hardware infrastructure supporting sending and receiving messages between distributed systems. MOM allows application modules to be distributed over heterogeneous platforms and reduces the complexity of developing applications that span multiple operating systems and network protocols. The middleware creates a distributed communications layer that insulates the application developer from the details of the various operating systems and network interfaces. APIs that extend across diverse platforms and networks are typically provided by MOM.
Psi is a free instant messaging client for the XMPP protocol which uses the Qt toolkit. It runs on Linux, Windows, macOS and OS/2.
Colloquy is an open-source IRC, SILC, ICB and XMPP client for Mac OS X. Colloquy uses its own core, known as Chat Core, although in the past it used Irssi as its IRC protocol engine. One of the primary goals behind Colloquy was to create an IRC, SILC and ICB client with Mac OS X visuals. Colloquy contains a user interface that follows Apple's Human interface guidelines in addition to containing support for traditional IRC command-line controls such as /nick and /join.
Google Talk was an instant messaging service that provided both text and voice communication. The instant messaging service was variously referred to colloquially as Gchat, Gtalk, or Gmessage among its users.
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, macOS, and Microsoft Windows. Released under the GPL-3.0-only 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".
Bombus is a GPL instant messaging client for the XMPP protocol. It is written in Java, and runs on Java ME/MIDP capable cellphones, including Windows Mobile platform with installed Java ME virtual machine, or any other platform, where Java ME is available. There was successful compilations of Bombue for Android.
Jingle is an extension to the Extensible Messaging and Presence Protocol (XMPP) which adds peer-to-peer (P2P) session control (signaling) for multimedia interactions such as in Voice over IP (VoIP) or videoconferencing communications. It was designed by Google and the XMPP Standards Foundation. The multimedia streams are delivered using the Real-time Transport Protocol (RTP). If needed, NAT traversal is assisted using Interactive Connectivity Establishment (ICE).
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 GPL-2.0-or-later. MCabber is the successor of Alejandro Jimenez Macias's 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).
Empathy is an instant messaging (IM) and voice over IP (VoIP) client which supports text, voice, video, file transfers, and inter-application communication over various IM communication protocols.
Fama IM is a free software instant messaging client for Linux and Unix that supports the use of multiple instant messaging protocols.
GNOME is a free and open-source desktop environment for Unix-like operating systems. GNOME was originally an acronym for GNU Network Object Model Environment, but the acronym was dropped because it no longer reflected the vision of the GNOME project.
Ayttm is a multi-protocol instant messaging client. It is the heir of the EveryBuddy project.
GNOME applications are those software that have been built with the GNOME philosophy in mind and follow the GNOME Human Interface Guidelines (HIG), they are hosted, developed, and managed in the GNOME official development infrastructure in the sub-domain of the official GNOME website at https://gitlab.gnome.org.
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 in to 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.
