GenEx: A simple generator structure for exclusive processes in high   energy collisions
  A simple C++ class structure for construction of a Monte Carlo event generators which can produce unweighted events within relativistic phase space is presented. The generator is self-adapting to the provided matrix element and acceptance cuts. The program is designed specially for exclusive processes and includes, as an example of such an application, implementation of the model for exclusive production of meson pairs $pp \rightarrow p M^+M^- p $ in high energy proton-proton collisions. 
R. A. Kycia, J. Chwastowski, R. Staszewski, J. Turnau
hep-ph