A free open source portable number theoretic multiple-precision integer library
copied from cf-post-staging / libtommathLibTomMath is a free open source portable number theoretic multiple-precision integer library written entirely in C. It's designed to provide a simple to work with API that provides fairly efficient routines that build out of the box without configuration. The library builds with GCC 2.95 and up as well as Visual C++ v6.00 and supports both static and dynamic linking.