Check yafu on github for the latest code.
YAFU (with assistance from other free software) uses the most powerful modern algorithms (and implementations of them) to factor input integers in a completely automated way. The automation within YAFU is state-of-the-art, combining factorization algorithms in an intelligent and adaptive methodology that minimizes the time to find the factors of arbitrary input integers.
Fast-Fourier-Transform-based number theory code to test Mersenne numbers for primality using the Lucas-Lehmer test and the Crandall-Fagin irrational-base discrete weighted transform (IBDWT) algorithm (Math. Computation 62 (205), pp.305-324, January 1994)