  This paper reports on a macroscopic fluctuation theory developed over the
last ten years in collaboration with L. Bertini, A. De Sole, D. Gabrielli and
C. Landim. This theory has been inspired by and tested on stochastic models of
interacting particles (stochastic lattice gases). It is the basis for a new
approach to the study of stationary non equilibrium states applicable to a
large class of systems. This overview emphasizes general ideas and for the
details I refer to the published papers.
