Open Source XMPP Software

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 is cross-platform powerful XMPP client designed for experienced users. There are builds available for MS Windows, GNU/Linux and macOS.

Psi is a cross-platform powerful XMPP client designed for experienced users. Psi+ is a development branch of Psi XMPP client. Previously is was a sort of fork but now just consider it as a space for nightly builds.

Pandion is an open source instant messaging client for XMPP networks. Keep in touch with friends or collaborate with colleagues using Pandion instant messenger. Pandion is designed for ease of use and secure communication.

Conversations is an open source Jabber/XMPP client for Android, designed to provide a unique and more freeing mobile messaging experience. XMPP is a federated protocol that can work with every XMPP server out there, giving you the freedom to choose a trustworthy server for yourself while still being able to chat with contacts from other servers. All communications are TLS encrypted and Conversations offers to enable one of two state of the art end-to-end encryption mechanisms, so you can be assured of the highest level of security in messaging. Conversations also offers plenty of unique features, such as image sharing, read markers, dynamic history loading and more.

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.

Kraken is a continuation of the Openfire IM Gateway plugin, but in a way that works for any XMPP server. It provides a way for XMPP users to log into, and communicate through, their legacy IM accounts such as AIM, ICQ, MSN, Yahoo, and friends.

climm is a portable, small, yet powerful console based, fully internationalized instant messaging client supporting the current v8 ICQ protocol and XMPP.

FireFloo is an Instant Messaging Communicator combining the open XMPP standard (Jabber, GMail Chat etc.) with the Echo Protocol for secured Chat and Messaging.

Rudel is a collaborative editing framework for GNU Emacs. It is designed to support multiple collaborative editing protocols such as the obby protocol.

a jabber (instant messaging) client running atop emacs.

This software allows a MUD server to be run as a Jabber bot. Users can then play the MUD using their Jabber client instead of a MUD client or telnet. This relieves the MUD server from having to handle user chat as users can chat in Jabber instead.

JabberMixClient is a IM Jabber client for portable devices, based on J2ME;JMC implements all the features of an IM client: contacts/presence management, single/multi user chat, users search, services discovery, GTalk and MSN transport.With 2 gui versions

A Jabber client written in C# using the .NET Compact Framework for use on Windows PCs and Windows Mobile PDAs. It is intended primarily to be deployed in a corporate environment where restricting the actions of users is desired.

The desktop application for Ribe - A Zimbabwean, African solution to FREE Chat & Messaging

Engroup is the web enterprise groupware promotes various collaboration methods plus adding company business management modules. Features are included: CRM, HRM, Document Management, Project Management, Chat, Wiki, Forum, News, Todo.

This is a less intrusive ajax web chat which uses Ajax, Smack, XMPP. This is the client version Servlet. The backend code should run under Tomcat server. You can use openfire or any other XMPP server as the server, gtalk also.

Akila’ize GChat IM is a free Instant Massager Chat client like Gtalk, Yahoo Messenger and IBM SameTime for Windows. Akila’ize GChat IM allows you to converse with your friends in Akila’ize Language. It is an alternative to Google Talk. Start sending messages in Akila’ize Language to your Google talk/Gmail friends and have fun Speaks out your conversation (Text to speech conversion – Enable/Disable anytime) Simple and Lite weight application

A realtime collaborative mind-mapping project. AmoebaChat allows the user to send and receive chat-style messages in an interconnected graph. This allows for a new way of communicating between parties that hasn't been explored yet.

Audible Alerts is a Pidgin (libpurple) plugin to produce notification of an IM audibly. It uses eSpeak, a text-to-speech program, to call out the name of the buddy who IMs you. You can download eSpeak from www.sourceforge.net/projects/espeak

Baraza is an Open Source mobile instant messaging server for Unix/Linux, implementing the Wireless Village/Instant Messaging and Presence Service (IMPS) protocol. The server supports inter-domain federation using IMPS SSP and Jabber/XMPP -www.baraza.im

Boltun is a chat bot plugin for Miranda IM with its own engine.

ButiFree is a project to develop a catalan card game online (called "La botifarra").

Кроссплатформенный IM на Java

Chat Back is a command line chat program. It is perfect to use when you have to chat, but don't have a graphical desktop or window system. At this time, it can be compiled on Windows and Linux and only has minimal support for Google Talk.