(formerly SimpleChat!) Fast, reliable, XHTML compatible web chat written in PHP and JavaScript.

A PHP chat script with unlimited users, rooms, and messages, IRC style commands, full message formatting. [Freeware]

A free, simple, fast and customizable chat server with file based storage. Includes documentation and release files.

A chat application that features multiple rooms, no browser refresh, database back-end, emotions, private messages, and multiple language support.

A nice script that lets create a simple chat in a few minutes. Requires MySQL. [Open source, GPL]

Allows users to post little blurbs on your website like a small guestbook/chat box. Inline or IFRAME, powered by mySQL.

Features include unlimited and private channels; moderators, whisper mode, timed sessions and multiple language support.

Modular service bot for IRC channels.

Free and open-source AJAX chat solution written in PHP with MySQL or PostgreSQL as storage back end. Site includes documentation and release files.