In this paper we present a software for 3D visualization and simulation of the microfabrications process utilized in the development of micro-electromechanical systems (MEMS). In the present version, the simulation of the process is based on a geometric approach and, differently from other academic and free distributed tools, the software developed here include modules for simulation of both, bulk and surface micromachning. An atomistic visualization module is also available. The software implement sophisticated rendering tools for coloring, illumination and transparency, as well as, tools to create and edit arbitrary 2D geometries and 3D solids. Respect to the simulation capabilities, the bulk micromachning module lead with the anisotropic etching of (100) oriented Si substrates in alkaline solutions (KOH), and 3D simulations are available for geometries with edges in just some specific angles (45 o , 90 o , concave and convex). The surface micromachning module is fully 3D operational, leading with the deposition and etching of up to 6 levels of structural and sacrificial films, which can be deposited on surfaces with complex 3D topography. Is also possible to simulate and visualize (with the transparency tool) the etching of sacrificial layers through holes in a covering structural layer and to deposit films on previously etched substrates. The atomistic module allows the observation of the corresponding crystalline structure underneath any results produced by the anisotropic etching simulator.