In films of superconducting tin, indium and aluminium it is possible to make constrictions on a scale smaller than the coherence length over a fairly large temperature range. The ground-state Cooper pairs in and around such a microbridge give rise to properties similar to those observed in classic Josephson tunnel junctions. However, in the microbridge the normal electrons thermally excited out of the superconducting ground state may be associated with very large current densities governed by a non-equilibrium transport equation, in contrast to the situation in a Josephson tunnel junction. This nonequilibrium current is responsible for some of the unique properties of superconducting microbridges.This review describes the Josephson behaviour of superconducting microbridges in terms of the resistively shunted junction model and how this behaviour manifests itself in experiment. Most of the observed deviations from this model must be treated on the basis of non-equilibrium theories. The present knowledge of the non-equilibrium properties of superconducting microbridges is reviewed from both an experimental and theoretical point of view.