A universal instant messaging (IM) program
See https://pidgin.im/about/ for more information. Pidgin is an instant messaging program which lets you log in to accounts on multiple chat networks simultaneously. It runs on Windows, Linux, and other UNIX operating systems. Pidgin is compatible with the following chat networks out of the box: AIM, ICQ, Google Talk, Jabber/XMPP, MSN Messenger, Yahoo!, Bonjour, Gadu-Gadu, IRC, MXit, Novell GroupWise Messenger, Lotus Sametime, SILC, SIMPLE, MySpaceIM, and Zephyr. It is written in C and makes heavy use of GLib and GTK+. Finch is a command line instant messaging program. It also lets you log in to accounts on multiple chat network simultaneously, and it is compatible with the same chat networks as Pidgin. It is written in C and makes heavy use of GLib and ncurses.
Psi IM — Qt-based XMPP client
Psi is cross-platform powerful XMPP client designed for experienced users. There are builds available for MS Windows, GNU/Linux and macOS.
Psi+ Project — development branch of Psi XMPP client
Psi is a cross-platform powerful XMPP client designed for experienced users. Psi+ is a development branch of Psi XMPP client. Project purpose: collection, refinement and writing new patches for transfer them to Psi upstream developers.
A multi-protocol instant messaging app for Mac OS X
Adium is an Open Source, multi-protocol instant messaging application for Mac OS X. Adium supports AIM, ICQ, Jabber, MSN, Yahoo!, Google Talk, Bonjour, Gadu-Gadu, Novell Groupwise, SIP/SIMPLE (Text), and Lotus Sametime. Additionally, it supports all of these applications at once so, even if you have multiple IM accounts, you don't have to log into each account separately.
A fork of pidgin which aims to provide minor features that have not been addressed by the pidgin development team (including manual textbox resizing). See funpidgin.sf.net for details.
A secure Jabber-client for Android using strong encryption
SecuXabber is a secure Jabber-client for Android that bases on Xabber and uses a strong, asymmetric enryption that works on top of the XMPP protocol. A key pair is generated on application start-up. Users can send their public key to other SecuXabber users via Bluetooth. This ensures the origin of the public key because people do a face-to-face check during key exchange. After the keys are imported by both users, all communication between them is done fully encrpyted using a strong 4096 bit end-to-end encryption.
Agora Web Messenger is an open-source client for the jabber protocol. It aims at provide a user-friendly interface for this wonderful protocol.
Chat Client/Serveur en Java basé sur le protocole XMPP. Ce chat permet d'avoir une interface graphique en 2D vue aérienne avec les autres chatteurs.
Jabbair is a project of a free and Open Source Jabber client working with AIR and developped in Actionscript 3 with Flex 3.
Egalite supports direct 1-1 chat with SSL over IPv4 or IPv6, as well as server based chat with IRC or XMPP (Jabber).