Gmsh is an automatic 3D finite element mesh generator (primarily
Delaunay) with build-in CAD and post-processing facilities. Its primal
design goal is to provide a simple meshing tool for academic test cases
with parametric input and up to date visualization capabilities. One of
its strengths is the ability to respect a characteristic length field for
the generation of adapted meshes on lines, surfaces and volumes, and to
mix these meshes with simple structured grids.

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.

WWW:  http://www.geuz.org/gmsh/