  We review some recent progress in our understanding of the phase diagram of
non abelian gauge theories, by varying their flavor content -- fermion
representations and the number of flavors. In particular, we explore the way
conformal symmetry can be restored before the loss of asymptotic freedom, and
through a subtle interplay of perturbation theory, chiral dynamics and
confining forces. It is with the combination of numerical lattice studies and
theoretical insights into gauge theories with and without supersymmetry that we
may successfully attempt to clarify the missing pieces of this puzzle.
