New Post: Is shared add-in possible?

Of course its possible.

You can find an example in the download package: "\Examples\Misc\C#\COMAddin Examples" called "Super Addin".
This sample Addin works in Excel, Word, PowerPoint, Outlook, Access and MSProject.

The solution contains 2 projects:

1) The known Shared-Addin way
2) Using the NO Tools layer

*Sebastian