An ActiveX control is essentially an OLE or Component Object Model (COM) object. It is a self-registering program or control; that is, it adds registry entries for itself automatically the first time it is run.
An ActiveX control can be as simple as a text box, as complex as an Office Viewer Component, and in some cases as complex as a small application. ActiveX controls are used as controls or dialogs for Internet Web sites, as add-ins to major applications from third-party vendors, and as plug-in utilities. Therefore, ActiveX is synonymous with Java, Netscape plug-ins, and scripting. However, the advantage of ActiveX over these other programming options is that ActiveX controls can also be used in applications written in different programming languages, including all of the Microsoft programming and database languages.
ActiveX controls are not stand-alone solutions. They can only be run from within host applications, such as Internet Explorer, a Microsoft Visual Basic® application, Visual C++® development system, Visual Basic, Delphi, DotNet for Applications, and so on. ActiveX controls facilitate the distribution of specialized controls over networks and the integration of those controls within Web browsers. This includes the ability of the control to identify itself to applications that use ActiveX controls.
Office Viewer Component is a standard
ActiveX Control. It can be integrated
into the other develop circumstance
supports the ActiveX Control.