Gpasman is a password manager. People working with the internet have to remember lots of passwords. Saving them in a textfile is not a secure idea. Gpasman is a GTK solution to this problem since it saves the password information encrypted, so now you have to remember only one password instead of ten (or more).
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.
passwdqc is a password/passphrase strength checking and policy enforcement tool set, including an optional PAM module (pam_passwdqc), command-line programs (pwqcheck and pwqgen), and a library (libpasswdqc). On systems with PAM, pam_passwdqc is normally invoked on password changes by programs such as passwd(1). It is capable of checking password or passphrase strength, enforcing a policy, and offering randomly-generated passphrases, with all of these features being optional and easily (re-)configurable. pwqcheck and pwqgen are standalone password/passphrase strength checking and random passphrase generator programs, respectively, and are usable from scripts. libpasswdqc is the underlying library, which may also be used from third-party programs.
TrinityOS is a step-by-step, example-driven HOWTO on building a very functional Linux box with strong security in mind. TrinityOS is well known for its strong packet firewall ruleset, Chrooted and Split DNS (v9 and v8), secured Sendmail (8.x), Linux PPTP, Serial consoles and Reverse TELNET, DHCPd, SSHd, UPSes, system performance tuning, the automated TrinityOS-Security implementation scripts, and much more.
ssh-keyinstall is a script that helps an ssh user set up the keys at both ends of an ssh connection. It creates an rsa or dsa key if needed and copies the public half to the server. Once the process is done, you'll be able to log in with the passphrase and key instead of a password.
Owl (Openwall GNU/*/Linux) is a small security-enhanced Linux distribution for servers. Owl also makes a good base system for customized virtual machine images and embedded systems, and Owl live CDs with remote SSH access are good for recovering or installing systems (whether with Owl or not). A single Owl CD includes the full live system, installable packages, the installer program, as well as full source code and the build environment capable of rebuilding the entire system from source. Owl supports multiple architectures (x86, x86-64, SPARC, and Alpha) and offers some compatibility for packages developed for other Linux distributions. The primary approaches to security are proactive source code review, privilege reduction, privilege separation, careful selection of third-party software, safe defaults, and "hardening" to reduce the likelihood of successful exploitation of security flaws.
Random Tools is a collection of tools you can use to collect random data and feed it to the kernel random pool. At present, only collecting from your sound card (/dev/dsp) is supported, but adding support for other sources of randomness (sometimes referred to as "entropy sources" or "random generators") should be easy. You can test the input with FIPS 140-2 tests before writing it to /dev/random.