jabberd is a Jabber/XMPP instant messaging server. It implements XMPP-Core (RFC3920), XMPP-IM (RFC3921), and a range of protocol extensions: XEP-0012, XEP-0016, XEP-0030, XEP-0049, XEP-0054, XEP-0077, XEP-0079, XEP-0092, XEP-0114, XEP-0138, XEP-0153, XEP-0157, XEP-0160, XEP-0191, XEP-0192, XEP-0193, XEP-0198, XEP-0199, XEP-0202, XEP-0203.
Saros is a Eclipse plugin for collaborative text editing that in particular targets distributed pair programming (also called remote pair programming), but can support arbitrarily many participants at once. All members of a session have an identical copy of an Eclipse project and Saros keeps these copies in sync as editing progresses.
Salut à Toi (or SàT: "Hi to You") is an XMPP/Jabber client with multi-frontends. You can use it on a desktop (Wix), with a console interface (Primitivus), as a command-line tool (jp), or on the Web (Libervia). A plugin architecture is used to make it modular. With SàT, you can perform all the expected XMPP functions (instant messaging, multi-user chat, file transfert, etc.), but you can also use your email client (MUA) to read and send your XMPP messages, play games, do microblogging, pipe Unix command results, make scripts, etc.
GOZERBOT is a channel bot that aids conversation in IRC channels and Jabber conference rooms. It's mainly used to serve RSS feeds and to have custom commands made for the channel. More then just a channel bot, GOZERBOT aims to provide a platform for the user to program his own bot and make it into something useful. This is done with a plugin structure that makes it easy to program your own. There are over 100 plugins already written and ready for use.
Scopserv Communicator is an audio/video Internet phone and instant messenger that supports some of the most popular VoIP and instant messaging protocols such as SIP, Jabber (XMPP), AIM/ICQ, MSN, Yahoo! Messenger, and a whole lot of other useful features. ScopServ Communicator is based on the SIP Communicator softphone.
Ibid is a multi-protocol, general purpose, instant messaging chat bot written in Python. It aims for a naturalistic interface rather than strict-syntax commands. Ibid understands many protocols, including IRC, Jabber/XMPP/Google Talk, Campfire, NMDC, and SILC. It also interacts over SMTP, HTTP, and various RPC protocols. Ibid aims to make plugins as easy as possible to write. It ships with a large collection of plugins for looking up information, performing conversions, storing factoids, delivering messages, and much more.