  A framework to represent and compute two-loop $N$-point Feynman diagrams as
double-integrals is discussed. The integrands are 'generalised one-loop type"
multi-point functions multiplied by simple weighting factors. The final
integrations over these two variables are to be performed numerically, whereas
the ingredients involved in the integrands, in particular the "generalised
one-loop type" functions, are computed analytically. The idea is illustrated on
a few examples of scalar three- and four-point functions.
