John the Ripper is a fast password cracker.  Its primary purpose is to detect 
weak passwords.  Besides several crypt(3) password hash types most commonly 
found on various Unix flavors, supported out of the box are Kerberos AFS and 
Windows NT/2000/XP/2003 LM hashes, plus several more with contributed patches.

This script includes an option to apply Ryan Lim's patch for JTR to support
MPI.  MPI allows you to use multiple processors on a system or even a cluster 
of systems for cracking passwords using JTR.  If you decide to apply this, you
will also need openmpi installed.  JTR's author does not recommend using the
patch, so use it at your own risk - for more information, see this link:
  http://www.openwall.com/lists/john-users/2005/08/24/4
This script also contains an optional "jumbo" patch, which enables processing 
of many password hash types and ciphers that are not otherwise supported.

Note this will not build in parallel; unset MAKEFLAGS if you have problems.
