CGI:IRC is a Perl/CGI program that lets you access IRC from a web browser, it is designed to be flexible and has many uses such as an IRC gateway for an IRC network, a chat-room for a website or to access IRC when stuck behind a restrictive firewall.
IQ is an intelligent, modular IRC robot written in PHP. IQ is modular, and can dynamically load and unload modules.
NoxBot is a generic IRC bot. It aims to be cross platform, modular, easy to use, featureful, easy for developing plugins, and mostly RFC compliant.
Nudelstats is a parser for irssi log files, producing XHTML output. It is based on irssistats 0.44, but uses a completely different approach to themes; they are stored outside the binary, in CSS format. This makes it slightly less portable, but much easier to change the themes.
PHP-IRC is a modular IRC bot written in PHP5 with a combination of object based/oriented programming. It operates under several different platforms with the purpose of automating common information related tasks on IRC.
Stumpele is a roleplaying irc-bot based on the idea of "beng the battlebot", rewritten in PHP. The goal is to provide a full battleengine for irc channels which is flexible and easily extendable.
t0xirc is a PHP class that enable your applications to interact with the popular IRC bot Eggdrop.
WebBot is a flexible IRC bot written in C capable of extracting information from a custom list of websites, including searchable ones, using regular expression patterns. HTTP GET and POST methods supported as well as HTTP redirects.
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.
ZPyIrc is a Web-based IRC client for Zope that allows you to set a client for as many clients you want on your Zope server.