  A Key feature of the minimal supersymmetric extension of the Standard Model
(MSSM) is the existence of a light Higgs boson, the mass of which is not a free
parameter but an observable that can be predicted from the theory. Given that
the LHC is able to measure the mass of a light Higgs with very good accuracy, a
lot of effort has been put into a precise theoretical prediction.
  We present a calculation of the SUSY-QCD corrections to this observable to
three-loop order. We perform multiple asymptotic expansions in order to deal
with the multi-scale three-loop diagrams, making heavy use of computer algebra
and keeping a keen eye on the numerical error introduced.
  We provide a computer code in the form of a Mathematica package that combines
our three-loop SUSY-QCD calculation with the literature of one- and two-loop
corrections to the Higgs mass, providing a state-of-the-art prediction for this
important observable.
