From September 2003 to August 2006 I have worked on the GenSpect project. In this project I have co-developed the mCRL2 language, which is a strongly compositional specification language that incorporates both the theory of process algebra and the theory of Petri nets. Using this language it is possible to do powerful verification. Various tools have been developed to contribute in achieving this goal.
From September 2006 to August 2008 I have worked on the NWO/Focus project VeriGEM: A Verification Grid for Enhanced Model Checking. The aim of this project was to design and build a distributed model-checking infrastructure for verifying system properties.
I am also interested in nominal techniques. Together with Murdoch Gabbay, I have developed nominal algebra, which is a theory of algebraic equality on nominal terms. We have applied to this to substitution, first-order logic and the lambda-calculus. See the papers for more information.