Neper is an advanced software designed for the modeling and simulation of polycrystalline materials. It facilitates the generation, manipulation, and analysis of polycrystalline microstructures in 2D and 3D, supporting various types of grain structures and orientations. Neper’s capabilities include the generation of synthetic microstructures using Voronoi tessellations, the import and meshing of experimental data, and the visualization and analysis of the resulting grain maps. It is extensively used in materials science for studying the mechanical and physical properties of polycrystals, offering features like grain boundary generation, texture analysis, and finite element meshing. Neper is known for its robust algorithms and efficiency in handling large-scale simulations, making it a valuable tool for researchers and engineers in the field of material science.