We present a method for computing stationary distributions for activated
processes in equilibrium and non-equilibrium systems using Forward Flux
Sampling (FFS). In this method, the stationary distributions are obtained
directly from the rate constant calculations for the forward and backward
reactions; there is no need to perform separate calculations for the stationary
distribution and the rate constant. We apply the method to the non-equilibrium
rare event problem proposed by Maier and Stein, to nucleation in a
2-dimensional Ising system, and to the flipping of a genetic switch