Shishi is a (still incomplete) implementation of Kerberos 5, which can be used to authenticate users in distributed systems. It contains a library that can be used by application developers, and a command line utility for users. Shishi supports Kerberos authenticated telnet client/server, IMAP client/server (via GSSAPI), SSH client/server (via GSSAPI), rsh/rlogin client, and a PAM module for host security.
Netzob supports the expert in reverse engineering, evaluation, and simulation of communication protocols. Its main goals are to help security evaluators to assess the robustness of proprietary or unknown protocol implementations, simulate realistic communications to test third-party products (IDS, firewalls, etc.), and create an Open Source implementation of a proprietary or unknown protocol. Netzob provides a semi-automatic inferring process, and includes everything necessary to passively learn the vocabulary of a protocol and actively infer its grammar. The learnt protocol can afterward be simulated. Netzob handles text protocols (like HTTP and IRC), fixed field protocols (like IP and TCP), and variable field protocols (like ASN.1-based formats).
A reasonable way to achieve a long term backup of OpenPGP (GnuPG, PGP, etc) keys is to print them out on paper. Due to metadata and redundancy, OpenPGP secret keys are significantly larger than just the "secret bits". In fact, the secret key contains a complete copy of the public key. Since the public key generally doesn't need to be backed up in this way (most people have many copies of it on various keyservers, Web pages, etc), only extracting the secret parts can be a real advantage. Paperkey extracts just those secret bytes and prints them. To reconstruct, you re-enter those bytes (whether by hand or via OCR), and paperkey can use them to transform your existing public key into a secret key.
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. It supports several crypt(3) password hash types commonly found on Unix systems, as well as Windows LM hashes. On top of this, lots of other hashes and ciphers are added in the community-enhanced version (-jumbo), and some are added in John the Ripper Pro.
OpenSAML is a portable implementation of the Security Assertion Markup Language (SAML) standard for the formation and exchange of authentication, attribute, and authorization data using XML, as defined by OASIS. There are interfaces for a range of languages, including C++ and Java.