a new user has to register with the website first by providing a user name
in the chat room, all messages should be displayed in chronological order with a timestamp and the user name of the user who has posted the message.
a marked message is generated and sent to the chat room each time a new user connects to the chat room or leaves the chat room.
a user list of all logged in users is displayed and updated
a user can send a message to one dedicated recipient (private message) instead of to all online users in the chat room
a user can send a message to defined subset of users (multicast); the recipients are informed about to whom this message was sent.
a user can send multi-media files to the participants of a chat room or via a private or multicast message, e.g., pictures, movies, sound files.