  I review the NLO QCD calculations of the branching ratio for B--> X_s gamma
in the SM. Including the leading electromagnetic corrections, one obtaines
BR(B-> X_s gamma)=(3.32 +- 0.30)*10^{-4}. Confronting theory with the newest
data, an updated value for |V_{ts}| is obtained: |V_{ts}|=0.037 +- 0.007.
Theoretical progress on the photon energy spectrum is also discussed. The
inclusive FCNC semileptonic decays in the SM are briefly summarized.
Furthermore, B--> X_s gamma is considered in 2HDMs and in different SUSY
scenarios. QCD corrections are shown to be crucial.
