OpenMP is described as 'The OpenMP API supports multi-platform shared-memory parallel programming in C/C++ and Fortran. The OpenMP API defines a portable, scalable model with a simple and flexible interface for developing parallel applications on platforms from the desktop to the supercomputer'. There are three alternatives to OpenMP for Linux, Mac, Windows and C++. The best alternative is Intel Threading Building Blocks, which is both free and Open Source. Other great apps like OpenMP are Dispenso (Free, Open Source) and Intel Parallel Studio XE (Paid).