  Modern spectroscopic experiments in few-electron atoms reached the level of
precision at which an accurate description of quantum electrodynamics (QED)
effects is mandatory. In many cases, theoretical treatment of QED effects has
to be performed without any expansion in the nuclear binding strength parameter
$Z\alpha$ (where $Z$ is the nuclear charge number and $\alpha$ is the
fine-structure constant). Such calculations involve multiple summations over
the whole spectrum of the Dirac equation in the presence of the binding nuclear
field, which can be evaluated in terms of the Dirac Green function. In this
paper we describe the technique of numerical calculations of QED corrections
with the Dirac Green function, developed in numerous investigations during the
last two decades.
