From the webpage:
Cambridge Advanced Modeller is a software tool for modelling and analysing the dependencies and flows in complex systems – such as products, processes and organisations. It provides a diagrammer, a simulation tool, and a DSM tool.
CAM is free for research, teaching and evaluation. We only require that you cite our work if you use CAM in support of published work. Commercial evaluation is allowed. Commercial use is subject to non-onerous conditions.
Toolboxes provide several modelling notations and analysis methods. CAM can be configured to develop new modelling notations by specifying the types of element and connection allowed. A modular architecture allows new functionality, such as simulation codes, to be added.
One of the research tool boxes is topic maps! Cool!
Have you used CAM?