John the Ripper is a fast password cracker. Its primary purpose is to detect weak Unix 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 LM hashes, as well as DES-based tripcodes, plus many more hashes and ciphers in "community enhanced" -jumbo versions and/or with other contributed patches.
The jumbo patch, which has been applied to this source tree of John the Ripper, adds a lot of code, documentation, and data contributed by the user community. This is not "official" John the Ripper code. It is very easy for new code to be added to the jumbo patch: the quality requirements are low. This means that you get a lot of functionality that is not "mature" enough or is otherwise inappropriate for the official JtR, which in turn also means that bugs in this code are to be expected, etc.