Now it is time for our theory to bear fruit and for us to harvest. In this chapter, we give a detailed description of weak wave turbulence in different media. We treat phonons, photons, magnons, plasmons, Rossby waves, surface water waves, and other. This is done by applying the general approaches from the previous chapters. The general model of wave turbulence adopted in this book is based on a detailed consideration of the wave–wave interaction. The action of an external environment is modeled by the function \(\Gamma (\boldsymbol k)\) that describes the rate of growth or decay. Nature is naturally more complex (for example, the interaction of water waves with wind and currents or wave–particle interactions in plasmas). Nevertheless, we believe that the following formulas and interpretations provide a good basis for further development of the theory of wave turbulence in various systems, each of which might require a separate monograph for an adequate detailed description.