  The initial stages of relativistic heavy ion collisions are studied
numerically in the framework of a 2+1 dimensional classical Yang-Mills theory.
We calculate the energy and number densities and momentum spectra of the
produced gluons. The model is also applied to non central collisions. The
numerical results are discussed in the light of RHIC measurements of energy and
multiplicity and other theoretical calculations. Some problems of the present
approach are pointed out.
