Suppose I want /app/controllers/test_controller.rb to be loaded automatically as normal, but in addition to that file, I''d like to load another file (say /sites/client1/app/controllers/ test_controller.rb) whose contents re-open the TestController class and add some functionality. Where would a good place be to add that in to the Rails code base? I''m looking at the ActiveController::Dependencies and ActiveSupport''s Dependencies modules and wondering where to start. Should I simply override the Dependencies::require_or_load method? A couple of questions come to mind: 1. Where does require_dependency come from? Is it a gem method? 2. How does the normal ''require'' method know that it has already loaded a file and doesn''t need to load it again? Is there anything I need to take in to account with regard to this feature so that Rails will do what I expect it to? (e.g. when in development mode, I want to be able to reload a page and get all changes, while in production mode I don''t want it to reload the class files each time.) The usefulness of this idea comes while trying to make a single application with one code-base which can be re-used for several of our clients, yet "tweaked" for further functionality if paid for. We''d like to be able to sell a "generic application" package and then optionally give our clients the opportunity to pay for customizations without duplicating the original code-base. Thank-you, Duane Johnson (canadaduane)