  Hard-sphere mixtures provide one a solvable reference system that can be used
to improve the density functional theory of realistic molecular fluids. We show
how the Kierlik-Rosinberg's scalar version of the fundamental measure density
functional theory of hard spheres [Phys. Rev. A, {\bf 42}, 3382 (1990)], which
presents computational advantages with respect to the original Rosenfeld's
vectorial formulation or its extensions, can be implemented and minimized in
three dimensions to describe fluid mixtures in complex environments. This
implementation is used as a basis for defining a molecular density functional
theory of water around molecular hydrophobic solutes of arbitrary shape.
