XMPP gateway to IRC.

Biboumi is a Free, Libre and Open Source XMPP gateway that connects to IRC servers and translates between the two protocols. Its goal is to let XMPP users take part in IRC discussions, using their favourite XMPP client.

Biboumi sources.

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.

Web-based XMPP/Jabber chat client written in JavaScript
Converse is a web based XMPP/Jabber chat client.
You can either use it as a webchat app, or you can integrate it into your own website.
It's 100% client-side JavaScript, HTML and CSS and the only backend required is a modern XMPP server.

the multi frontend, multipurpose communication tool
SàT covers a large spectrum of the Internet functions and uses:

Chat with one or many contacts, in public or private rooms.
Organize contact groups and restrict the visibility of your messages.
End-to-end encryption makes your communications private.
Blogging system to share instant thoughts or write longer articles.
File sharing, games, interaction with other networks.

An XMPP chat client for your website

Complete customer support solution - feedback service, helpdesk, chat

Free & Flexible & Open source - Live Support chat for your website. Web and desktop clients. XMPP notifications, GTalk, Jabber, OpenFire, Chrome extension, Node.js support, MySQL, PostgreSQL

AstLinux is a "Communications and Network Appliance" open source software distribution. Unified communications including voice, presence and messaging, provided by Asterisk (SIP, DAHDI) and Prosody (XMPP). AstLinux's framework allows integrators and developers to deploy solutions that may be remotely monitored, supported and upgraded using an optimized 40 MB image.

Metronome is the XMPPd which runs on LW.Org IM and from recently also on Jappix's official service.

Prosody is a modern flexible communications server for Jabber/XMPP written in Lua. It aims to be easy to set up and configure, and light on resources. For developers it aims to be easy to extend and give a flexible system on which to rapidly develop added functionality, or prototype new protocols.

Prosody is licensed under the permissive MIT/X11 license.