Depending on your needs, SOM may be something you will want to explore. For more information on SOM, see the February 1998 issue of MacTech magazine which contains articles on SOM and the Contextual Menu Manager. COM is Microsoft's Component Object Model. For more information on COM and ActiveX read the June 1997 issue of MacTech Magazine. Once you understand the basic concepts described in this article, you will begin to find new uses for plug-ins in your application.
Many applications have areas that can be logically broken out into a plug-in architecture.
The key is to understand and then experiment. Don't use this approach if you don't need it, but if you do, you can easily add years of life to your application by opening it up to yourself and third-party developers in this way. I look forward to hearing about how you've used this introductory plug-in architecture.