Emc2 is a portable, interactive, graphical editor of two-dimensional mesh
geometries. It can create and modify geometries (as in CAD), and define line
discretizations, subdomains, and reference numbers (to take into account
boundary conditions and material properties). Grid and Delaunay-Voronoi
meshes composed of triangles or quadrilaterals can be regularized, rotated,
and modified via the addition, removal, or moving of vertices.

It is suggested that users also install the math/bamg port.