NTL is a high-performance, portable C++ library providing data structures and algorithms for manipulating signed, arbitrary length integers, and for vectors, matrices, and polynomials over the integers and over finite fields. By default, NTL is thread safe. NTL is distributed under LGPLv2.1+ (i.e., LGPL version 2.1 or later) [more details] If you are interested in contributing to the development o