MMesh3D: a 3D elliptic mesh generation tool for simply connected domains with topography. Main features: Structured ELLIPTIC mesh generator for 3D volumes [1]; Quadtree mesh refinement; Boundary orthogonality and automatic grid control [9]; Generation of Hexahedral and Prismatic elements; Topography readable from Digital Elevation Model (DEM) data files (from NOAA); Topography readable from the ETOPO Global Relief model of NOAA [5,6]; Cube sphere.