Showcase features a Message Passing Architecture by which add-ins control Showcase using structured Messages sent to the Showcase interpreter. This feature is discussed more fully in [X-ref to Showcase Architecture]. For now, it is important to note that Messages normally pass invisibly between Showcase and its add-ins, but can be made visible, in real-time, in the Showcase Console.
All Messages (including those from your own add-ins) are now displayed in a separate Console window.