Component Object Model (COM) and Distributed Component Object Model (DCOM) provide the foundation for Microsoft's distributed object strategy. They are the glue that should enable Microsoft to bring their other core products and technologies such as ActiveX, Internet Information Server, and Internet Explorer to the enterprise. In other words, this is Microsoft's answer to CORBA, Netscape, and JavaBeans. This text discusses: how to use COM and DCOM with existing legacy systems; how COM and DCOM fit into two- and three-tier client/server architectures; Thin versus Thick Clients and how they relate to Microsoft's Active Server Platform; new technologies from Microsoft such as Viper and Falcon; and security issues for distributed objects.