ParaDiGM: Parallel Distributed General Mesh

ParaDiGM (Parallel Distributed General Mesh) is an open-source C library (LGPL) designed to overcome the technological bottlenecks associated with geometric data handling and mesh manipulation in massively parallel numerical simulations. Originally developed as the geometric engine for the CWIPI coupling library, it has evolved into a standalone infrastructure designed to manage distributed meshes at the billion-element scale and beyond. Unlike traditional mesh infrastructures, ParaDiGM acts as a non-intrusive progressive middleware. It provides solvers (CFD, structural mechanics, high-order Discontinuous Galerkin) with a suite of low-level services for hybrid partitioning, point cloud location, and wall distance computation, all while ensuring the dynamic load balancing essential for exascale performance. With native APIs for C/C++, Fortran, and Python/NumPy, ParaDiGM seamlessly integrates into existing production codes—such as CEDRE, elsA, SoNiCS or Maia — transforming static data structures into dynamic and highly scalable geometric environments.