Visual Basic 5.0 allows users to extend an object. Extending an object means changing the object's behavior by writing code to handle events and add properties, methods, and events. Using this capability, end users can create customized classes by combining an ActiveX designer, a frame supplied by Visual Basic, and a code module. In a similar manner, end users can attach code to documents, creating customized documents.
Because the ActiveX designers you distribute can be customized by end users, you need to understand the object extensions model and be aware of the types of behavior changes that are possible. For more information, see Chapter 5, "Type Information and Extended Objects," and the Automation Programmer's Reference.