IceChat is an IRC ( Internet Relay Chat) program. It is used to connected to up to 10 IRC Servers simultaneously and chat in channels to other IRC Users. IceChat started in 2000, and has gone through many changes in its user Interface, its design, and of course its many features.
Wollabot is a modular service bot for IRC channels. It's written entirely in PHP making it crossplatform and easy to customize. It's not supposed to be guarding channels and does not contain such functionality thus increasing performance for the tasks it is supposed to do. It comes bundled with a couple of modules eg. a PHP function prototype lookup and a Google lookup tool.
SmartIRC is a PHP class for communication with IRC networks, which conforms to the RFC 2812 (IRC). It's an API that handles all IRC protocol messages. This class is designed for creating IRC bots, chats and show irc related info on webpages.