Emc2 is a portable, interactive and graphic software Edition of two dimensional geometry and mesh. We can create and modify the geometry (CAD), define the discretization on the lines, define the subdomains, and define some reference numbers to take into account the boundary conditions and material properties. The elements of the mesh are triangles and quadrilaterals. We have two kind of meshes: grid mesh and Delaunay Voronoo (automatic mesh). We make the edition of the mesh by moving, removing, adding vertices, by regularization, or by transformations (symmetry, rotation,..), etc. Suggested add-on: the port math/bamg.