Chat Client with Website Registration

I am looking for a simple chat client that can be used over the internet. I require an online registration process that is held in a database, the users can be assigned user or moderator privileges, the database should hold user name, password, privledge ie user or moderator, age, gender. Based on that the client should be an executable program that can be installed on a persons PC. the chat client needs to allow for multiple room entry, private chatting, and avatars that users can change to their liking.