Separation of concerns is a basic engineering principle that is also at the core of object-oriented analysis and design methods in the context of the Unified Modeling Language (UML). The UML gives the designer a rich, but somehow disorganized, set of views on her model as well as many features, such as design pattern occurrences, stereotypes or tag values, allowing her to add nonfunctional information to a model. Aspect-oriented concepts are applied to manage the multitude of design constraints. However, it can then be an overwhelming task to reconcile the various aspects of a model into a working implementation. In this paper, we present our UMLAUT framework as a toolkit for easily building application specific "weavers" for generating detailed design models from high level, aspect oriented UML models. This is illustrated with a toy example of a distributed multimedia application with a weaving generating an implementation model. More ambitious applications are briefly outlined in the conclusion.