The βπ3D finite element (FE) library is a tool for computational modeling of engineering applications. The library provides a framework for discretization of three-dimensional 1 multiphysics problems described by systems of partial differential equations. βπ3D can be compiled in real or complex mode to accommodate the need for real-or complex-valued physics variables, respectively. The library is written entirely in Fortran; user applications interfacing with the library are also written in Fortran. The βπ3D software can be installed and runs efficiently on various CPU-based compute architectures, from laptops and single workstations to state-of-the-art supercomputers.