Creating modern software is a challenging but also a very creative task. Especially in early development phases like requirements engineering or architectural design software engineers use different mediums to manifest their thoughts and to discuss possible ambiguities. These mediums range from analog tools like pen \& paper or whiteboards to digital ones like tablet pc's or smartboards. Whereas editing capabilities for analog mediums are restricted to add/remove operations, there already is great support in the digital world to later move, rotate or even share thoughts and diagrams with distributed teams. In addition the tool support for creating complex diagrams used to express software architecture and design along with sophisticated techniques like code generation is large. However, most of these tools restrict the user input to valid data, decreasing the software engineers flexibility which is why they often fall back to non formal tools. This doctoral thesis aims to combine the flexibility of informal sketching with the power of formal software engineering tools. As part of this thesis, a new generic framework will be created which dynamically augments new and already existing diagram editors with sketch-based input features.