  The calculation of the Landau gauge gluon propagator performed in Coimbra
using lattice QCD simulations is reviewed. Particular attention is given to the
behavior of the gluon propagator in the infrared region and the value of
$D(0)$. In the second part of the article, the modeling of the lattice data
using massive type propagators and Gribov type propagators is discussed. Four
different mass scales are required to describe the propagator over the full
range of momenta accessed by the simulations discussed here. Furthermore,
assuming a momentum dependent gluon mass, we sketch on its functional
dependence.
