Component Object Model (COM)

Controls

ActiveX controls (.OCX).

ActiveX controls include all the normal buttons, text boxes and other controls seen on windows application forms. Custom ActiveX controls can be developed to provide some new functionality in a familiar control or a totally new control. These are developed as ActiveX controls to provide encapsulation of function and ease of reuse.

Some of the controls that I have developed include a Seven Segment Display, a 5X7 Dot Matrix Display and a Command Button with integral LED.

Servers

In Process servers(.DLL).

Dll's are generally written in conjunction with a windows application to contain functions that do a specific task that can be re-used in other applications. An example of these tasks could be communication with the internet or a mathematics function library. The code in these modules are referred to as 'in process servers' as they run in the same memory space as the calling application.

Out Of Process servers(.EXE).

Out of Processes servers are developed for much the same reasons that in process servers are written. The chief difference between them is that out of processes servers execute in their own memory space. This means that in some cases they are ideally suited for background tasks.