micrOMEGAs4.1: Two dark matter candidates.

micrOMEGAs  is a code to compute dark matter observables in generic extensions of the standard model. This version of micrOMEGAs  includes a generalization of the Boltzmann equations to take into account the possibility of two dark matter candidates. The modification of the relic density calculation to include interactions between the two dark matter sectors as well as semi-annihilation is presented. Both dark matter signals in direct and indirect detection are computed as well. An extension of the standard model with two scalar doublets and a singlet is used as an example.