ActiveX is [Microsoft]'s marketing term for a set of software technology based on [COM].
When someone talks about ActiveX, they typically mean ActiveX controls
[http://www.microsoft.com/com/tech/ActiveX.asp], which are components
(that may or may not have a visible representation in a [GUI]) that can be embedded in an application.
To allow this embedding, ActiveX controls must implement specific COM interfaces. 
For example, a [Visual Basic] application may display a GUI containing widgets which are ActiveX controls.
[Internet Explorer] can download and run an ActiveX component in the browser window
(if you gave permission to install it).

Tcl extensions that support ActiveX in some way include [ActiveTcl] ([Tcl Dev Kit], both via [tcom]), [TclScript], [Optcl], [TclControl], [Noel Frankinet]'s [AxTcl] (well, not really ''his''),
[Joe Mistachkin]'s [TclBridge],
...

The [tcom] extension provides basic COM access, and does not specifically support the 
COM interfaces for interacting with ActiveX controls.
That is, [Optcl] implements and accesses the COM interfaces required for
embedding ActiveX controls in Tk, while tcom does not.

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[AxTcl80] relates to OLE and supposedly is related to [AcTcl]/TclOCX.

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[Category Interprocess Communication] - [Category Windows]