An extension of OLE that allows visual software components, created in any language, to be embedded easily into forms and web pages. Active X is a “brand” referring to a broad family of COM based technologies that were originally part of the OLE family. [Microsoft Windows]

ActiveX is Microsoft’s name for a set of object-oriented program technologies and tools. An ActiveX component (ActiveX control) is a self-sufficient software module that can execute in an ActiveX container application such as Internet Explorer, Outlook, Excel, and Word. Most HMIs and data analysis tools are also ActiveX containers, so it is possible to “plug-in” one vendor’s ActiveX control is another vendor’s ActiveX container application. ActiveX is Microsoft's answer to Sun Microsystems’ Java. Thus, an ActiveX control is roughly equivalent to a Java applet. ActiveX files typically have a file name suffix of OCX or VBX (Visual Basic Control). ActiveX components use COM/DCOM to exchange data with other software components.

There are commercial ActiveX components that enable programmers to quickly implement OPC communication capabilities within an application.

See also Applet, COM, and DCOM.