We are using a COM Object automation model to make our application available to our customers.
They are using for the most part python to access our applicaton interface.
As we want to be able to install (not yet run, that's another issue) different versions of the application, we are changing our COM components to be regfree.
But that conflicts with the access from scripting languages through IDispatch automation since they need the entries in the registry.
Our approach is to create an application which manages the active version of our actual application. It lets the user decide which version he wants to have and it takes care of the registry entries.
What are the alternatives to our approach?
There is a protocol within COM for doing this. If you version the Interfaces (and change the GUIDS for each version) you can install multiple versions. Microsoft does this with WORD etc.
It is possible to create a Word.Document.5 class which is specific to version 5 of the library, or just word.Document which will create an instance of the highest present on the machine. I'm not sure if this functionality is build into COM or needs to be impemented but it's worth looking into.