Thanks to the unique control of physical parameters in laser-cooled atomic systems, recent experiments with mixtures of bosons and fermions have observed dual Bose-Fermi superfluid mixtures. This breakthrough is the culmination of an effort started with the first observation of superfluidity in ³He. In this chapter we describe the techniques that enabled this discovery. We discuss the collisional stability of the mixture and we show how the study of inelastic losses can be used as a probe of short range correlations in ultracold gases. We will also focus on the dynamics of Bose-Fermi superfluid counterflow and we will explore the origin of dissipation in this system.