OpenMP

''The OpenMP Application Program Interface (API) supports multi-platform shared-memory parallel programming in C/C++ and Fortran on all architectures, including Unix platforms and Windows NT platforms. Jointly defined by a group of major computer hardware and software vendors, OpenMP is a portable, scalable model that gives shared-memory parallel programmers a simple and flexible interface for developing parallel applications for platforms ranging from the desktop to the supercomputer.'' The extract above is from the official [http://www.openmp.org OpenMP] web page. There is plenty of information about [http://www.openmp.org OpenMP] there, and many other places on the web.