Broadcast is an essential building block of most MANETs (Mobile Ad hoc Networks) protocols. For example, most routing protocols use broadcasting to establish routes or to transmit an error packet for an invalid route. Since the communication range of nodes is limited and nodes are battery powered, optimizing energy consumption is one of the key factors to be considered when engineering broadcasting algorithms. More precisely, to increase the lifetime of such networks, efficient use of energy is a critical issue, because significant energy is consumed by the redundant broadcasted messages. In this paper, we first present a classification of most broadcasting protocols used in MANETs. A short description of each class is provided followed by a description of some adaptive broadcasting protocols.