The numerical treatment of partial differential equations with particle methods
and meshfree discretization techniques is a very active research field both in
the mathematics and engineering community. Due to their independence of a mesh,
particle schemes and meshfree methods can deal with large geometric changes of
the domain more easily than classical discretization techniques. Furthermore,
meshfree methods offer a promising approach for the coupling of particle models
to continuous models. This volume of LNCSE is a collection of the proceedings
papers of the Fourth International Workshop on Meshfree Methods held in
September 2007 in Bonn. The articles address the different meshfree methods
(SPH, PUM, GFEM, EFGM, RKPM, etc.)