COM (Component Object Model) 기초

COM: a binary standard that enables software components to inter-operate in a networked environment regardless of the language in which they were developed

"local" 서버에 등록 (that are instantiated with CreateObject)

COM+: 

- evolution of Microsoft COM and MTS. 

- handles many of the resource management tasks that you previously had to program yourself, such as thread allocation and security. 

- makes your applications more scalable by providing thread pooling, object pooling, and just-in-time object activation

- administrators can deploy and administer COM+ applications through a graphical user interface, or automate administrative tasks using a scripting or programming language. 

- Software developers can use COM+ to visually configure routine component and application behavior, such as security and participation in transactions, and to integrate components into COM+ applications.

Component Services (COM+) consists of the latest version of COM, distributed COM (DCOM), and Microsoft Distributed Transaction Coordinator (DTC), plus additional functionality. With COM+, 

To open COM+, click Start, point to Programs, point to Administrative Tools, and then click Component Services. Component Services is also available in Transaction Integrator (TI) Manager as follows: Start TI Manager and double-click the Component Services folder.

Component Services provides standard application functionality for administration, deployment, security, reliability, and scalability. Component Services simplifies the administrator's work by providing a tool for administering all applications visually through a single user interface.

COM+ contains some enhandced features.
YOu can call com server  in dotnet compoenet.you can not directly communicate with com from dotnet client. You will have to use proxy (Runtime callable wrapper) to communicate between them.
Com and Com+ is considerend unmanaged because they do not contain the assembly meta data.
Com and com+ are binary standard.
Extension of com and com+ component is dll.

DCOM: Distributed-COM. The protocol that enables a COM object to be instantiated on another computer from the one that is using the code (ie. call from a client machine in London, but the code runs on the machine in New York)

ActiveX control: client side 에서 실행됨

ATL (Active Template Library): a set of template-based C++ classes that let you create small, fast COM objects. It has special support for key COM features, including stock implementations, dual interfaces, standard COM enumerator interfaces, connection points, tear-off interfaces, and ActiveX controls.

Introduction to COM and COM+

The Component Object Model (COM) is a "binary" standard that enables software components to interoperate in a networked environment regardless of the language in which they were developed.

Dividing software into clients and objects enables you to use those clients and objects as building blocks that can be combined and reused in many different ways by many different clients, just as standard building materials can be used to construct many different structures.

COM and COM+ are the key technologies that provide the infrastructure that enables clients and objects to work together. Other key COM concepts include methods, interfaces, classes, references, and components, which build on the foundation of clients and objects.

This section contains:

• COM Defined
• COM+ Defined
• Component Services Features
• Distributed Applications
• Automation
• COM Objects
• COM Methods
• COM Interfaces
• COM Classes
• COM Component and TI Component
• Viewing COM Classes, Interfaces, and Methods
• Windows Script Host COM Client

What is COM? Microsoft COM (Component Object Model) technology in the Microsoft Windows-family of Operating Systems enables software components to communicate. COM is used by developers to create re-usable software components, link components together to build applications, and take advantage of Windows services. COM objects can be created with a variety of programming languages. Object-oriented languages, such as C++, provide programming mechanisms that simplify the implementation of COM objects. The family of COM technologies includes COM+, Distributed COM (DCOM) and ActiveX® Controls. Microsoft provides COM interfaces for many Windows application programming interfaces such as Direct Show, Media Foundation, Packaging API, Windows Animation Manager, Windows Portable Devices, and Microsoft Active Directory (AD). COM is used in applications such as the Microsoft Office Family of products. For example COM OLE technology allows Word documents to dynamically link to data in Excel spreadsheets and COM Automation allows users to build scripts in their applications to perform repetitive tasks or control one application from another.

What is COM+?

COM+ is the name of the COM-based services and technologies first released in Windows 2000. COM+ brought together the technology of COM components and the application host of Microsoft Transaction Server (MTS). COM+ automatically handles programming tasks such as resource pooling, disconnected applications, event publication and subscription and distributed transactions.