Today you get Bopup Instant Messaging Suite for free. There are three parts to Bopup Instant Messaging Suite: Communication Server, Messenger, and Observer. Bopup Communication Server is installed on the computer or server that you want to use as your main node; this is the computer or server that all your other computers will connect to. Bopup Messenger and Bopup Observer are installed on the computers which you want to use instant messaging on; these computers connect to the computer or server that has Bopup Communication Server installed. The difference between Messenger and Observer is, Messenger is a full instant messaging program that can send and receive messages and files while Observer only receives messages and files.