The GENIE Universal, Object-Oriented Neutrino Generator

A Universal Object-Oriented/C++ Neutrino Monte Carlo Generator (GENIE) is briefly described. The purpose of this large scale software system is to become the 'canonical' Monte Carlo for Neutrino Interaction Physics whose validity will extend to all neutrino types and nuclear targets in the energy range from few MeV to few hundred GeV. GENIE attempts to unify the Monte Carlo generation approaches used by a host of different, smaller procedural systems in a modern object-oriented software design. It is already a mature software system that currently consists of ∼100,000 lines of C++ code (∼350 classes organised in ∼40 packages).