An application framework is a collection of classes implementing the shared architecture of a family of applications. A technique is proposed for defining the specialization interface of a framework in such a way that it can be used to automatically produce a task-driven programming environment for guiding the application development process. Using the environment, the application developer can incrementally construct an application that follows the conventions implied by the framework architecture. The environment provides specialization instructions adapting automatically to the application-specific context, and an integrated source code editor which responds to actions that conflict with the given specialization interface. The main characteristics and implementation principles of the tool are explained.