Club House

We want a chat system in which there are multiple chat rooms (or groups). When a user logs in, he is assigned to a predetermined chat group. Each user may be a moderator of one group and an attendee of another group, according to his user profile in the database. We must be able to specify that a given user is a moderator of no group, or that a given user is an attendee of no group. A user who is both a moderator of one group and an attendee of another must be in two chat rooms at once - there should be no problems with this. An attendee can nudge the moderator of his group to attract his attention. A moderator can communicate both privately or publicly with any attendee in his group via chat and voice. Any user can see which users should be in his chat group, and which users are logged on. The chat windows must take up only a portion of the screen - 200-300 pixels wide, 600-1000 pixels tall. In any chat room the moderator must be able to specify the font for the chat room. The chat system must be accompanied by a database. All software used must be open source - no .NET, ASP, or VB.