Nek5000 is an open source, highly scalable and portable spectral element code designed to simulate
Written in Fortran 77 and C it relies on MPI for parallelization and on a subset of LAPACK routines for eigenvalue computations, depending on the particular solver employed. In addition, it can be optionally coupled with MOAB, which provides an interface to meshes generated with CUBIT. Nek5000 output formats can be read by the parallel visualization package VisIt developed at LLNL/LBNL. VisIt is mandatory for large problems (e.g. more than 100,000 spectral elements).