  This article describes three Mathematica packages for the automatic
calculation of one-loop Feynman diagrams: the diagrams are generated with
FeynArts, algebraically simplified with FormCalc, and finally evaluated
numerically using the LoopTools package. The calculations are performed
analytically as far as possible, with results given in a form well suited for
numerical evaluation. The latter is straightforward with the utility programs
provided by FormCalc (e.g. for translation into Fortran code) and the
implementations of the one-loop integrals in LoopTools. The programs are also
equipped for calculations in supersymmetric models.
