To complement the ActiveX control there is plug-in project that shares many of the same files. This allows browsers and environments that support the Netscape Plug-in Architecture to display ActiveX controls. These include:

• Mozilla 1.x
• Netscape Navigator 3.x
• Netscape Communicator 4.x
• Netscape 6.x, 7.x
• Opera 
• QT Toolkit for Windows (via the QNPlugin NPAPI wrapper classes)
• CodeWeavers CrossOver Plug-in

There have been previous plug-ins for Netscape Navigator/Communicator that host ActiveX controls but most such as the NCompass plug-in are defunct.

This is the first open source implementation and also one of the lightest and fastest as well because it uses ATL rather than MFC.

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Personalmente ho provatio la cosa e funziona bene , solamente ci sono dei "notevoli" problemi di installazione, nel senso che decide lui quando installarsi correttamente... :(

Fonte: Mozilla ActiveX Plug-in