  Some results about dissipative processes in superfluids are presented. We
focus on fermionic superfluidity and restrict our analysis to the contribution
of phonons to bulk viscosity, shear viscosity and thermal conductivity. At
sufficiently low temperatures phonons give the dominant contribution to the
transport coefficients if all the other low energy excitation of the system are
gapped. We first consider a system of cold fermionic atoms close to the
unitarity limit. Then we turn to the superfluid phase of quark matter that may
be realized at high baryonic density.
