There seems to be very little information on this. Almost every topic on
MSDN concerning containing ActiveX documents now says the topic will no
longer be updated due to release of VS.NET. The only exception to that is
the MFC documentation. It appears that MFC will support ActiveX documents
(containers and servers) using C++ in VS.NET, but that is just bringing the
app forward to use the new C++ compiler, not migrating to a .NET
architecture. It's life support for apps like mine and someday they will
pull the plug. It also is unmanaged code and doesn't provide easy access
the .NET framework.

What is the .NET alternative to ActiveX document containment? A brief
explanation of what we use it for: In our application, the user are
following a set of precedural steps and signing off when they are performed.
Sometimes the user will embed an Excel or Word document as supporting
documentation for work performed. We activate these documents inside our
application for editing and reviewing. We store the document as part of our
file's data (structured storage) for practical and possibly legal reasons.
say "possibly" because it fortunately has not ever been put to the test,
it was felt that a single intact file was better proof of exactly how the
steps were performed and with what documentation was used. Anyway, what
would the ".NET way" be to do something like this?