The notion of integrable system in classical mechanics dates back to Joseph Liouville (1809-1882) and has an illustrious and long history. The modern resurgence of activity was spurred by the analysis of soliton solutions of nonlinear wave equations like the Korteweg-deVries and Kadomtsev-Petviashvili equations. This renewed interest brought along the invention and development of far reaching techniques of solution, including the inverse scattering method and the Sato-Segal-Wilson theory of infinite Grassmannians.
Topics: Dynamical systems and ergodic theory