WWWChat allows your users to chat interactively with each other on your web site. It's easy to set up and allows you to have as many users in a room as possible. The script is very small and fast. It won't hog system resources when many attempt to enter the system. Customizable to feature unlimited number of chat rooms.
Users can create a room and only the owners can kick someone.
The owners can give the ownership to another users. This version uses the client-pull method. It even comes with an Administration tool for easy maintenance of private rooms. Free EveryChat is fast, simple to use, and easy to set up. Completely platform and browser independent.