  The basic concepts of a generalized relativistic density functional approach
to the equation of state of dense matter are presented. The model is an
extension of relativistic mean-field models with density-dependent couplings.
It includes explicit cluster degrees of freedom. The formation and dissolution
of nuclei is described with the help of mass shifts. The model can be adapted
to the description of finite nuclei in order to study the effect of
$\alpha$-particle correlations at the nuclear surface on the neutron skin
thickness of heavy nuclei. Further extensions of the model to include quark
degrees of freedom or an energy dependence of the nucleon self-energies are
outlined.
