The detection and resolution of conflicts among norms are key processes to guarantee the proper behavior of multi-agent systems (MAS) regulated by norms. A way of regulation is required to restrict and guide the autonomous and possibly heterogeneous software agents that act according to their own interests. When norms are applied to regulate MAS, normative conflicts may arise. A conflict between norms is a situation in which the fulfillment of a norm causes a violation of another one. We present and compare different techniques proposed to detect and resolve conflicts.