Yalst ("yet another live support tool") is a powerful chatting tool that integrates easily with any Web site. The highlights are visitor and operator initiated chats, audio and video chats, visitor monitoring and tracking with alarm functionality, form monitoring, file transfers in both directions during chats, plugin-free co-browsing, marketing tools (push banners, URLs, messages, and customized surveys), ad-tracking of campaigns, conversion tracking, departments, a FAQ database, a customized contact form (if chat is offline), chat between operators, and an application programming interface for deep Web site integration.
php Free Chat is a simple, fast, and customizable chat server that uses the filesystem for message and nickname storage. It uses AJAX to smoothly refresh and display the chat zone and the nickname zone. It supports customized CSS stylesheets and a plugin system that allows you to write your own storage routines.
NoxBot is a modular IRC bot that uses the platform independence of PHP. NoxBot is easy to use and features many commands that can be given to the bot over IRC. There are the many available modules. If NoxBot does not provide exactly what you need, then it can be easily implemented as a module. NoxBot tries to stay as RFC-complaint as possible. Some of its features include authentication, module management, a help system, multi-lingual support, timers, a storage system that separates modules, and many more.