Systems, methods, and computer products for deriving custom cache dependencies are explained. A framework that includes an extensible cache dependency base class that can be used to derive custom cache dependency classes for invalidating cache entries on some custom condition is disclosed. In some embodiments, a Web page server includes a cache and the framework including the extensible cache dependency base. Methods are disclosed for causing a cache entry to be dependent on a customized cache dependency and for invalidating cache entries based on customized cache dependencies. For example, cache entries can depend on and be purged based on dependencies on database tables and Web services.