Chatroom Site

I want to make a chatroom site. The first page should be a welcome and login. I want to make 20 rooms and have unlimited visitors. If you have a demo please show me. The chatroom should be simple to use and work very fast. no flash or shlow chatrooms. I need speed and also want to customize the colors. Again I want to make many rooms and be able to have thousands of visitors since I will have a lot of chatters. show me a link to your demo. please do not copy/paste your company biography.