Gmsh is a free 3D finite element grid generator with a build-in CAD
engine and post-processor. Its design goal is to provide a fast, light
and user-friendly meshing tool with parametric input and advanced
visualization capabilities. Gmsh is built around four modules:
geometry, mesh, solver and post-processing. The specification of any
input to these modules is done either interactively using the graphical
user interface or in ASCII text files using Gmsh's own scripting
language.