η production in Hadronic interactions

A short, and definitely not a complete representation of eta production processes on hadrons is given. First of all, the different ways of obtaining the piN --> etaN and piN --> etaN amplitudes are presented. After that, an over-view of results obtained using these amplitudes as input for calculating processes like: NN --> etaNN, pd --> eta(3)He, pid --> etaNN and etad, eta(3)He and eta(4)He as well as eta-light nuclei 3 states, will be given. The experimental and theoretical results will be reviewed. The open problems and the way how to solve them will be presented.