The book begins with one of the most approachable and effective tours of COM you're likely to find anywhere. The author covers COM components along with fundamental terms (such as interfaces, globally unique identifiers (GUIDs), IUnknown, and the registry) with a minimum of hassle. In a section on OLE Automation, the author shows how to use VB to script Excel spreadsheets, while explaining the details of early and late binding, IDispatch, and dual interfaces.

Next the author discusses how to build components, starting with ActiveX servers (both dynamic-link libraries [DLLs] and standalone EXEs) and proceeding to ActiveX controls. (The section on building controls is particularly strong, with good coverage of Ambient and Extender objects and connection points for event handling.) Throughout, VB COM relies on tools-based examples, with plenty of screen shots from VB 6 tools (such as its Class Builder Wizard). Later the book moves on to the enterprise with coverage of Distributed COM (DCOM), multitiered architectures, Microsoft Transaction Server (MTS), and emerging standards such as COM+.