The Second World Congress on Social Simulation was held in Fairfax, USA on 14-17 July 2008. It was jointly organised by PAAA (Pacific and Asia), NAACSOS (North America) and ESSA (Europe). Invited speakers were Joshua M. Epstein (Brookings Institution, USA), Dirk Helbing (ETH Zurich, Switzerland) and Hiroshi Deguchi (Tokyo Institute of Technology, Japan)