Joker the IRC bot is a PHP class designed for quick and easy IRC bot construction. This base class contains methods that can be executed from your plugins. It has built-in flood protection, timers, and a powerful plugin system that allows you to reload plugin classes on-the-fly, without restarting the PHP console or disconnecting from the network.
Synovel Collabsuite provides email, calendaring, and instant messaging solution for enterprises. It consists of a Linux email server with calendar and IM, a Web-based administration panel, a desktop client suite that runs on Windows and Linux, and AJAX-based Web mail access. It uses open standards for communications: IMAP, POP, and SMTP for email, CalDav for calendaring, and Jabber for IM.
JTelIRC is an advanced IRC framework for Java. It is mainly intended for writing automated clients ("bots"), but may be used for normal clients as well. It provides an intuitive and well documented Java interface to IRC and makes it extremely easy to write advanced clients quickly.
Funpidgin is a modified version of the Pidgin instant messenger application. It was made in response to the controversial auto-resizing textbox that was implemented in Pidgin. Current features of Funpidgin include manual resizing and the ability to turn off persistent window placement. Funpidgin's releases are meant to coincide with Pidgin's releases.