Hi Kevin,

>How do you see this working for backward compatibility with existing projects that don't currently have an I-Layer?

Backward compatibility is an important issue, of course. But I think the worst case is, that people have subclassed C-Layer classes, which is probably being done a lot of times. If you would introduce an I-Layer a typical class hierarchy would probably look like this:

cBaseForm
 iBaseForm
   cBizObjForm
     iBizObjForm
       aBizObjForm

If there are own subclasses it currently looks like this:

cBaseForm
 myBaseForm
 cBizObjForm
   myBizObjForm
     aBizObjForm

If an MM update would contain an I-Layer the result would be:

cBaseForm
  myBaseForm
  iBaseForm
   cBizObjForm
     myBizObjForm
     iBizObjForm
       aBizObjForm

The subclasses the user has created in a previous version, would still be derived from the C-Layer, but all new subclasses created after the Update could be made from the I-Layer.

Please tell me, if I'm missing something important here!

Regards,
Armin