>>But I'm with you - the actual differences are obscure and would benefit from serious clarification (not just 'they have different suffixes').
>
>Right. We need some clear definitions here. Actually, the extensions don't matter. You can change them to anything else and the ActiveX/COM will work fine (assuming that it is registered with the changed extension).
>

My understanding of the difference between an ActiveX Control and a COM server is that an ActiveX control can participate in the Windows Event loop of a process directly, while COM objects can't directly do so.