  Recent progress in constructing holographic models for QCD is discussed,
concentrating on the bottom-up models which implement holographically the
renormalization group flow of QCD. The dynamics of gluons can be modeled by
using a string-inspired model termed improved holographic QCD, and flavor can
be added by introducing space filling branes in this model. The flavor fully
backreacts to the glue in the Veneziano limit, giving rise to a class of models
which are called V-QCD. The phase diagrams and spectra of V-QCD are in good
agreement with results for QCD obtained by other methods.
