Today formalisms with graphical representations are used to model structure, behaviour, and other views on software and systems. The UML is just one example for modelling languages with graphical representation of its models. Although most models are executable without explicit graphical information of the model?s elements, the appearance of a model is of particular importance for its readability. To improve the so called embedding of a graph representing a model or to create a initial embedding, an algorithmic support for arranging the elements is useful. We provide a software environment in which layout algorithms can be developed and evaluated. By defining proper interfaces for graph elements, we provide easy access to our library of layout algorithms for external use.