mCRL2 is a toolset for model checking concurrent processes.
Models are specified in the mCRL2 process algebra; formal properties can be formulated in the modal mu-calculus.
I have worked on several ways to improve the underlying algorithms for model checking.
The tools I have developed are 
lpssymbolicbisim, 
pbessymbolicbisim and 
pbespor.
lpssymbolicbisim and 
pbessymbolicbisim are symbolic tools for infinite-state model checking.
They operate on 
linear process specifications (LPSs) and 
parameterised Boolean equation systems (PBESs), respectively.
pbespor solves PBESs through instantiation, but tries to reduce the underlying graph by applying 
partial-order reduction.
Furthermore, I have also made significant improvements to the tools 
lpsparunfold and 
pbesconstelm.