On the way in to work yesterday I listened to (see my previous post) Martin Fowler's article on the Dependency Injection pattern. It's a good and thorough treatment of the subject, as I'm sure you'd expect. The connection to the Plug-in pattern in his "Patterns of Enterprise Application Architecture" made me wonder whether Roy Osherove's Plug-in Framework used a similar mechanism. It would appear that Roy's scheme uses a single IPlugin interface to simplify matters, whilst still providing an application with "extensibility hooks" (the main intention of the article, after all). I wonder how easy it would be to extend Roy's framework to support some level of dependency injection?