Parse::CPAN::Meta is a parser for META.json and META.yml files, using JSON::PP and/or CPAN::Meta::YAML.

This module understands the ICal date/time and duration formats, as defined in RFC 2445. It can be used to parse these formats in order to create the appropriate objects.

The Benchmark::Timer class allows you to time portions of code conveniently, as well as benchmark code by allowing timings of repeated trials. It is perfect for when you need more precise information about the running time of portions of your code than the Benchmark module will give you, but don't want to go all out and profile your code.

This module converts Perl data structures to JSON and vice versa.

This module splits a set of data with IDs and arbitrary values into one test file per (key+value) for easy parallelisation.

This module is about the native integer numerical data type. A native integer is one of the types of datum that can appear in the numeric part of a Perl scalar. This module supplies constants describing the native integer type. Both signed and unsigned representations are handled.

Config::Any provides a facility for Perl applications and libraries to load configuration data from multiple different file formats. It supports XML, YAML, JSON, Apache-style configuration, and Perl code.

The Digest::MD4 module allows you to use the RSA Data Security Inc.: MD4 Message Digest algorithm from within Perl programs. The algorithm takes as input a message of arbitrary length and produces as output a 128-bit "fingerprint" or "message digest" of the input. MD4 is described in RFC 1320.

A Sub::Override module that makes it easy to override subroutines. Particularly useful for mocking in tests.

This package transparently speeds up functions by caching return values, trading space for time.

This module converts Perl data structures to MessagePack and vice versa. MessagePack is a binary-based efficient object serialization format. It enables to exchange structured objects between many languages like JSON. But unlike JSON, it is very fast and small.

This module allows errors from a clan (or family) of modules to appear to originate from the caller of the clan. This is necessary in cases where the clan modules are not classes derived from each other, and thus the Carp.pm module doesn't help.

perlcritic is a Perl source code analyzer. It is the executable front-end to the Perl::Critic engine, which attempts to identify awkward, hard to read, error-prone, or unconventional constructs in your code. Most of the rules are based on Damian Conway's book "Perl Best Practices". However, perlcritic is not limited to enforcing PBP, and it will even support rules that contradict Conway. All rules can easily be configured or disabled to your liking.

Crypt::UnixCrypt_XS implements the DES-based Unix crypt function. For those who need to construct non-standard variants of crypt, the various building blocks used in crypt are also supplied separately.

CPAN::Changes helps users programmatically read and write Changes files that conform to a common specification.

Hash::FieldHash provides the field hash mechanism which supports the inside-out technique. It is an alternative to Hash::Util::FieldHash with a simpler interface, higher performance, and relic support.

Type::Tiny is a small class for writing type constraints, inspired by Moose's type constraint API. It has only one non-core dependency (and even that is simply a module that was previously distributed as part of Type::Tiny but has since been spun off), and can be used with Moose, Mouse and Moo (or none of the above).

DateTime::Format::ISO8601 is a DateTime extension that parses almost all ISO8601 date and time formats.

This module is an implementation of the BGP-4 inter-domain routing protocol. It encapsulates all of the functionality needed to establish and maintain a BGP peering session and exchange routing update information with the peer. It aims to provide a simple API to the BGP protocol for the purposes of automation, logging, monitoring, testing, and similar tasks using the power and flexibility of perl. The module does not implement the functionality of a RIB (Routing Information Base) nor does it modify the kernel routing table of the host system. However, such operations could be implemented using the API provided by the module.

Devel::CheckCompiler is a tiny module to check whether a compiler is available. It can test for a C99 compiler, or you can tell it to compile a C source file with optional linker flags.

This module provides basic Boolean support, by defining two special objects: true and false.

Devel::OverloadInfo returns information about overloaded operators for a given class (or object), including where in the inheritance hierarchy the overloads are declared and where the code implementing it is.

App::cpanminus is a script to get, unpack, build and install modules from CPAN and does nothing else. It's dependency free (can bootstrap itself), requires zero configuration, and stands alone. When running, it requires only 10MB of RAM.

Sys::Hostname::Long tries very hard to get the full hostname of a system.