This chapter summarizes some related work on both the classical (Section 3.1) and the eventual (Section 3.2) leader election problems. Each of these sections presents existing algorithms of the literature for static and dynamic systems. In static systems, nodes can fail and recover, as presented in Section 2.6.1, whereas in dynamic systems, nodes can move, join and leave the system, as well as fail and recover, as described in Section 2.6.2.