abcde is a frontend to cdparanoia, wget, cd-discid, id3, and your favorite Ogg Vorbis (the default), MP3, FLAC, Ogg Speex, or MPP (Musepack) encoder. It grabs an entire CD and converts each track to the desired format, then comments or ID3-tags each file, all with one command. It supports multiple output in a single CD read, the creation of a single track from a CD, resume operation, CD concatenation, volume normalization, gapless encoding (with LAME), parallelization, SMP, proxies, customizable filename organization and munging, playlist generation, distributed encoding via distmp3, and more.
BW whois is a modern whois client that works as a full-featured Web application or as a commandline tool. It is flexible and configurable with self-detecting CGI support, multiple security options in the CGI mode, a mature TLD table, database caching (using MySQL or PostgreSQL), and many more options and features.
The Date::Calc package consists of a (pure-Perl) wrapper which either loads Date::Calc::XS (a separate implementation in C and XS) or Date::Calc::PP (a pure-Perl implementation which is part of the Date::Calc package). The Date::Calc::XS and Date::Calc::PP modules perform all kinds of date calculations based on the Gregorian calendar (the one used in all Western countries today), according to relevant norms and standards: ISO/R 2015-1971, DIN 1355 and, to some extent, ISO 8601 (where applicable). The package is designed as an efficient toolbox, not a bulky ready-made application. It provides extensive documentation and examples of use, multi-language support, and special functions for business needs.
Makepp, a build program that has a number of features that allow for reliable builds and simpler build files, is a drop-in replacement for GNU make. It supports almost all of the syntax that GNU make supports, and can be used with makefiles produced by utilities such as automake. It is called makepp (or make++) because it was designed with special support for C++, which has since been extended to other languages like Swig or embedded SQL. Some features that makepp adds to make are: greatly improved handling of builds that involve multiple makefiles (recursive make is no longer necessary); automatic scanning for include files; rebuilds triggered if build command changes; checksum-based signature methods for reliable builds, smart enough to ignore whitespace or comment changes; extensibility through Perl programming (within your makefile); repositories (automatically importing files from another tree); and build caches (not recompiling identically what a user of the same cache already did).
mysqldiff is a Perl script which compares the data structures (i.e. table definitions) of two MySQL databases and returns the differences as a sequence of MySQL commands suitable for piping into mysql which will transform the structure of the first database to be identical to that of the second (c.f. diff and patch). Database structures can be compared whether they are files containing table definitions or existing databases, local or remote.
The PerlDL project aims to turn Perl into an efficient numerical language for scientific computing. The PDL module gives standard Perl the ability to compactly store and speedily manipulate the large N-dimensional data sets which are the bread and butter of scientific computing. e.g. $a=$b+$c can add two 2048x2048 images in only a fraction of a second. The aim is to provide tons of useful functionality for scientific and numeric analysis.
The Sethi Family Guestbook is a multi-format guestbook script written as a single PHP file that requires no installation. It features page spanning, (optional) private comments, user-selection of number of entries per page to display, multiple guestbook formats (elegant, simple, or standard), and background color. No database is required. It supports image verification using random text as part of a CAPTCHA system. It also uses other techniques to foil spam robots. It supports multiple formats, mangled email display, and a fully customizable interface.
Class::Date provides a date datatype for Perl. You can create new Class::Date objects with a constructor from different scalar formats, array refs, and hash refs, and then you can easily manipulate it by the builtin "+" and "-" operators (e.g., $date=date([2001,03,15])+'3Y 1s'). Relative date types also available.