HERWIG 6.4 Release Note
  A new release of the Monte Carlo program HERWIG (version 6.4) is now available. The main new features are: spin correlations between the production and decay of heavy fermions, i.e. top quarks, tau leptons and SUSY particles; polarization effects in SUSY production processes in lepton-lepton collisions; an interface to TAUOLA for tau decays; MSSM Higgs processes in lepton-lepton collisions. 
G. Corcella, I.G. Knowles, G. Marchesini, S. Moretti, K. Odagiri, P.   Richardson, M.H. Seymour, B.R. Webber