  We study the equilibration of a class of far-from-equilibrium strongly
interacting systems using gauge/gravity duality. The systems we analyse are 2+1
dimensional and have a four dimensional gravitational dual. A prototype example
of a system we analyse is the equilibration of a two dimensional fluid which is
translational invariant in one direction and is attached to two different heat
baths with different temperatures at infinity in the other direction. We
realise such setup in gauge/gravity duality by joining two semi-infinite
asymptotically Anti-de Sitter (AdS) black branes of different temperatures,
which subsequently evolve towards equilibrium by emitting gravitational
radiation towards the boundary of AdS. At sufficiently late times the solution
converges to a similarity solution, which is only sensitive to the left and
right equilibrium states and not to the details of the initial conditions. This
attractor solution not only incorporates the growing region of equilibrated
plasma but also the outwardly-propagating transition regions, and can be
constructed by solving a single ordinary differential equation.
