MPIR is an open source multiprecision integer (bignum) library forked from the GMP (GNU Multi Precision) project. It consists of much code from past GMP releases, in combination with much original contributed code. A brief introduction can be found here Introduction(French) MPIR is constructed by a developer and vendor friendly community of professional and amateur mathematicians, computer scientists and hobbyists. The primary goals of the MPIR project are: To have a developer friendly community. To foster links with hardware and software vendors. Development of parallel algorithms for multiprecision arithmetic including support for GPU’s and other multicore processors. To provide build support out-of-the-box for Linux, Apple, Sun and Microsoft Windows systems. To overall license the project with the GNU LGPL license. To maintain full interface support with GMP - MPIR is a drop-in replacement for GMP. Support for building MPIR using Microsoft Visual Studio 2010 for use in both 32-bit and 64-bit versions of Windows.