>>I think that perhaps your reference to WinZip might have caused the confusion.
>
>I believe Mike is referring to this: Thread #923845

I am not quite sure I understand the licensing issue here.
Are we allowed to use Namespaces from shell.application? If they are found in the registry, and there is no Windows OS warnings or limitations, then what is not legal to use them? I believe it is the issue between MS and other parties, not between developers and DynaZip. How developer may know that it is not legal to use this particular Namespace?

For .zip files the NameSpace is documented in HKEY_CLASSES_ROOT\.zip\CompressedFolder\ShellNew\Data.