The embedding features date from Windows 3.x era, and I think fully came to be with Office 97 or 2000, either of which was implemented fully as set of COM objec

The embedding features date from Windows 3.x era, and I think fully came to be with Office 97 or 2000, either of which was implemented fully as set of COM objects with OLE Automation interfaces and essentially embeddable in everything - if you deliver an application on Windows and can specify Office license in your requirements, suddenly you can do a lot more - for example, I've used programs that simply embedded Excel for data entry features, not just as "can import from specially prepared Excel sheets" but directly embedded Excel sheet editor in their GUI and stored Excel data streams internally to their document formats.