This edition of « Panoramas et Synthèses » follows the thematic trimester « Singularities in Mechanics » that was organized at the Institut Henri Poincare during winter 2008 by Jens Eggers, Christophe Josserand and Laure Saint-Raymond.

The central questions - which are discussed in a transverse way - are the formation, the propagation and the microscopic description of singularities. This volume gathers different articles showing the variety of mathematical approaches and physical problems, ranging from surface singularities in fiuid mechanics to self-similar solutions of the Non Linear Schrödinger equation. In fluid mechanics, the wave breaking dynamics is investigated (Yves Pomeau and Martine Le Berre), the evolution of vortex filaments (Valeria Banica and Luis Vega) as well as the formation and cusps in surface flows (Jens Eggers

and Marco Fontelos) while the mathematical grounds of such singularities are described for capillary flows (Antoine Mellet) and two dimensional surface flows (Claude Bardos and David Lannes).