Abstract Solitons kinks and the like are manifestation of weakly nonlinear excitations in action. On the other hand strongly nonlinear phenomena (say, vibration of a genuinely anharmonic lattice) exhibit a completly different solitary patterns, which as a rule are nonanalytic. The compacton, a soliton, or a breather, with a compact support, is a typical example of such phenomenon wherein the nonlinear dispersion degenerates at the edge of the pulse and confines the pulse to a finite domain. Some of these compactons travel and collide elastically. Other compact structures have a fixed support (equalibria or breathers). Certain compacton-supporting cases can be related to the conventional concept of integrabilty, but most of these phenomena are represent completly novel structures. A typical novel structure is that of a compact breather generated by an anharmonic lattice embedded in a specific site potential.