integer factorization with the Elliptic Curve Method (ECM)

 pyecm is a Python program to factor numbers using the Elliptic Curve Method
 (ECM). It is relatively fast in that it can quickly factors numbers up to 50
 digits.
 .
 Because it is written in Python, pyecm is very portable. It is also fairly
 easy to use. Use of python-gmpy and/or python-psyco will speed it up
 immensely.