This pragma allows you to declare constants at compile-time. When a constant is used in an expression, Perl replaces it with its value at compile time, and may then optimize the expression further. In particular, any code in an if (CONSTANT) block will be optimized away if the constant is false.

This package provides functions to convert between Roman and Arabic algorisms. It supports both conventional Roman algorisms (which range from 1 to 3999) and Milhar Romans, a variation which uses a bar across the algorism to indicate multiplication by 1000.

This module provides some XS functions to assist in writing syntax modules that provide new perl-visible syntax, primarily for authors of keyword plugins using the PL_keyword_plugin hook mechanism.

This module packages several Moose::Util::TypeConstraints with coercions, designed to work with the DateTime suite of objects.

Carp::Assert::More is a set of handy assertion functions for Perl.

This module facilitates using Moose or Mouse modules without changing the code. By default, Mouse will be provided to libraries, unless Moose is already loaded, or explicitly requested by the end-user. End users can force the decision of which backend to use by setting the environment variable ANY_MOOSE to be Moose or Mouse.

This package implements usleep, ualarm, and gettimeofday for Perl, as well as wrappers to implement time, sleep, and alarm that know about non-integral seconds.

Crypt::PasswdMD5 provides various crypt()-compatible interfaces to the MD5-based crypt() function found in various *nixes. It is based on the implementation found on FreeBSD 2.2.[56]-RELEASE.

Pod::Spell is a Pod formatter whose output is good for spellchecking.

Pod::Spell is rather like Pod::Text, except that it doesn't put much effort into actual formatting, and it suppresses things that look like Perl symbols or Perl jargon (so that your spellchecking program won't complain about mystery words like "$thing" or "Foo::Bar" or "hashref").

File::Zglob provides a traditional Unix glob functionality; it returns a list of file names that match the given pattern. For instance, it supports the **/*.pm form.

Authen-Passphrase is the base class for a system of objects that encapsulate passphrases. An object of this type is a passphrase recogniser; its job is to recognise whether an offered passphrase is the right one. For security such passphrase recognisers usually do not themselves know the passphrase they are looking for; they can merely recognise it when they see it. There are many schemes in use to achieve this effect and the intent of this class is to provide a consistent interface to them all. In addition to the base class, this module also contains implementations of several specific passphrase schemes.

PPI::XS provides (minor) XS acceleration for PPI.

IPC::Run allows you run and interact with child processes using files, pipes, and pseudo-ttys. Both system()-style and scripted usages are supported and may be mixed. Likewise, functional and OO API styles are both supported and may be mixed.

Data::Dump::Streamer provides ways to accurately serialize a data structure as Perl code.

The Getopt::Long module implements an extended getopt function called GetOptions(). It parses the command line from ARGV, recognizing and removing specified options and their possible values.

This function adheres to the POSIX syntax for command line options, with GNU extensions. In general, this means that options have long names instead of single letters, and are introduced with a double dash "--". Support for bundling of command line options, as was the case with the more traditional single-letter approach, is provided but not enabled by default.

Provides several perl modules for date/time manipulation: Time::CTime.pm, Time::JulianDay.pm, Time::ParseDate.pm, Time::Timezone.pm, and Time::DaysInMonth.pm.

This module is meant as a debugging aid. It can be used to make a script complain loudly with stack backtraces when warn()-ing or die()ing.

Hash::MultiValue is an object (and a plain hash reference) that may contain multiple values per key, inspired by MultiDict of WebOb.

The Error package provides two interfaces. Firstly Error provides a procedural interface to exception handling. Secondly Error is a base class for errors/exceptions that can either be thrown, for subsequent catch, or can simply be recorded.

The Digest::JHash module allows you to use the fast JHash hashing algorithm developed by Bob Jenkins from within Perl programs. The algorithm takes as input a message of arbitrary length and produces as output a 32-bit "message digest" of the input in the form of an unsigned long integer.

This package provides a package to change terminal modes and perform non-blocking reads.

This module implement a UDP client for the statsd statistics collector daemon in use at Etsy.com.

This module provides a convenient way to perform cleanup or other forms of resource management at the end of a scope. It is particularly useful when dealing with exceptions: the Scope::Guard constructor takes a reference to a subroutine that is guaranteed to be called even if the thread of execution is aborted prematurely. This effectively allows lexically-scoped "promises" to be made that are automatically honoured by perl's garbage collector.

This class is the base class for all time zone objects. A time zone is represented internally as a set of observances, each of which describes the offset from GMT for a given time period. Note that without the DateTime module, this module does not do much. It's primary interface is through a DateTime object, and most users will not need to directly use DateTime::TimeZone methods.