John the Ripper "Jumbo" password cracker
John the Ripper is a fast password cracker, currently available for many flavors
of Unix, Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak
Unix passwords. Besides several crypt(3) password hash types most commonly found
on various Unix systems, supported out of the box are Windows LM hashes, plus lots
of other hashes and ciphers.