  The version 3.01 of ELMAG, a Monte Carlo program for the simulation of
electromagnetic cascades initiated by high-energy photons and electrons
interacting with extragalactic background light (EBL), is presented. Pair
production and inverse Compton scattering on EBL photons as well as synchrotron
losses are implemented using weighted sampling of the cascade development. New
features include, among others, the implementation of turbulent extragalactic
magnetic fields and the calculation of three-dimensional electron and positron
trajectories, solving the Lorentz force equation. As final result of the
three-dimensional simulations, the program provides two-dimensional source
images as function of the energy and the time delay of secondary cascade
particles.
