[en] In this paper the authors present a brief review of theoretical and experimental results concerning the relaxation modes of the contact line between a solid, a liquid and a gas. This study constitutes a first step in view of the elucidation of wetting of non-homogeneous surfaces. The dispersion law giving the characteristic relaxation rate as a function of the wavevector of the deformation is derived from the balance of elastic driving force and dissipation processes. The very anomalous form of the dispersion law is confirmed by experimental measurements achieved on model surfaces using an original method to deform periodically the line