  I discuss recent advances in the understanding of non-equilibrium gauge field
dynamics in plasmas which have particle distributions which are locally
anisotropic in momentum space. In contrast to locally isotropic plasmas such
anisotropic plasmas have a spectrum of soft unstable modes which are
characterized by exponential growth of transverse (chromo)-magnetic fields at
short times. The long-time behavior of such instabilities depends on whether or
not the gauge group is abelian or non-abelian. Here I will report on recent
numerical simulations which attempt to determine the long-time behavior of an
anisotropic non-abelian plasma within hard-loop effective theory.
