An application framework is a collection of classes implementing the shared architecture of a family of applications. It is shown how the specialization interface ("hot spots") of a framework can be annotated with specialization patterns to provide task-based guidance for the framework specialization process. The specialization patterns define various structural, semantic, and coding constraints over the applications derived from the framework. We also present a tool that supports both the framework development process and the framework specialization process, based on the notion of specialization patterns. We will outline the basic concepts of the tool and discuss techniques to identify and specify specialization patterns as required by the tool. These techniques have been applied by the tool. These techniques have been applied in realistic case studies for creating programming environments for application frameworks.