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.
smake is a highly portable 'make' program that makes commands up to date based on rules in Makefiles and on the timestamps of the related files. It implements a complete superset of the features of the classical POSIX/Unix make program. It warns about typical misuse of dynamic macros that prevent portability of makefiles. Its automake features allow you to run scripts to automatically create rules for unknown platforms.
Zsh is a UNIX command interpreter (shell) which of the standard shells most resembles the Korn shell (ksh). It includes enhancements of many types, notably in the command-line editor, options for customising its behaviour, filename globbing, features to make C-shell (csh) users feel more at home and extra features drawn from tcsh.
Dim is a utility to help you track the changes of items (sets composed of multiple files). It provides commands to handle the complete lifecycle of version control operations: create a library, register users (code authors), create items, save local versions, branch, clone, export, import, remove, merge, archive, replicate library content over the network or the filesystem, and access the full history and browse differences at the library, item, file, line, or word level. Dim is a single self-documented POSIX shell script. It just uses standard Unix utilities like awk, diff, tar, and openssl.
The parallel project allows for simple parallel and distributed processing from shell scripts. In particular, the programs accept lines of shell code on the standard input and run these lines in parallel. The parallelism can be either on the local machine or on a cluster, if a small amount of time is taken to set up SSH. Additionally, the distributed version includes a degree of fault tolerance.
FrAid (Fr[actal] Aid) is a programming language that is appropriate for mathematical computations, visualization, batch processing, and more. It features both a standalone application that provides a programming environment for the language and a system for integrating the language with Java. The Java interface allows mathematical equations and formulas to be used with Java code, making it easier to process numerical computations, symbolic computations, imaging, CAD, and more.
flipflip's podcast downloader is a script that downloads podcasts. Is has options to limit the number of podcasts to download, to rename the downloaded files based on rules, and to tag the MP3 files with custom content or with content derived from the feed metadata. The program is very small and has very few dependencies (id3v2 and wget).
Config::Maker takes a file with data in simple hierarchical format (similar to BIND and DHCP configuration files) and several templates, and produces the text by filling in the values. It is mainly useful for creating related configuration files. It can be used to generate firewall configuration scripts, DNS zone files, DHCP configuration files, a reference from a single file with all users and machines, etc. It's useful when you are not satisfied with keeping information synchronized in several places, but don't want something as complex as cfengine. Snippets of Perl can be used if all else fails.