Check the HTTP response code for a link

https://metacpan.org/release/HTTP-SimpleLinkChecker

Get the byte size of an internet resource

https://metacpan.org/release/HTTP-Size

Lightweight field hash implementation

https://metacpan.org/release/Hash-FieldHash

Flatten, unflatten complex data hashes

https://metacpan.org/pod/Hash::Flatten

Merges hashes

https://metacpan.org/release/Hash-Merge

Perl extension to provide the stuff missing in Hash::Util

https://metacpan.org/release/Hash-MoreUtils

Perl extension to store multiple values per key

http://search.cpan.org/dist/Hash-MultiValue/

Perl extensions for keeping data partially sorted

https://metacpan.org/release/Heap

Lexically scoped subroutine wrappers for Perl

https://metacpan.org/release/Hook-LexWrap

Abstract Base Class to build modules to capture output

https://metacpan.org/release/IO-Capture

Capture STDOUT/STDERR from subprocesses and XS/C modules

https://metacpan.org/release/IO-CaptureOutput

Perl5 compression modules (bzip2, deflate, gzip, zlib, zip)

https://metacpan.org/release/IO-Compress

Open an HTML file with automatic charset detection

https://metacpan.org/release/IO-HTML

Perl extension for working with IO::Handle like objects

https://metacpan.org/release/IO-Handle-Util

IO::Multiplex - Manage IO on many file handles

https://metacpan.org/release/IO-Multiplex

Portably create pipe() or pipe-like handles, one way or another

https://metacpan.org/release/IO-Pipely

Easy interface to IO::Pty

https://metacpan.org/release/IO-Pty-Easy

Supporting module for SOAP::Lite

http://search.cpan.org/dist/IO-SessionData/

Perl module with object interface to AF_INET6 domain sockets

https://metacpan.org/release/IO-Socket-INET6

Drop-in replacement for IO::Socket::INET supporting IPv4 and IPv6

https://metacpan.org/release/IO-Socket-IP

Perl5 interface to SSL sockets

https://metacpan.org/release/IO-Socket-SSL

Simplified Perl5 module to handle I/O on in-core strings

https://metacpan.org/release/IO-String

Flexible I/O Perl5 module that allows manipulation of pseudo-TTYs

http://search.cpan.org/dist/IO-Tty/

IO:: style interface to Compress::Zlib

https://metacpan.org/release/IO-Zlib

Use IO handles with non-file objects

https://metacpan.org/release/IO-stringy

Fast lookup of country codes from IP addresses

https://metacpan.org/release/IP-Country

Run subprocesses with piping and redirection

https://metacpan.org/release/IPC-Run

Run a subprocess in batch mode

https://metacpan.org/release/IPC-Run3

Simple interface to access shared memory

https://metacpan.org/release/IPC-ShareLite

IPC::Signal - Utility functions dealing with signals

https://metacpan.org/release/IPC-Signal

Perl extension to run commands simply with detailed diagnostics

https://metacpan.org/release/IPC-System-Simple

Database connection caching and organization

https://metacpan.org/release/Ima-DBI

Perl module for getting image information

https://metacpan.org/release/Image-Info

Sequentially read Image::Magick object from a filehandle

https://metacpan.org/release/Image-Magick-Iterator

Helper functions for PBM/PGM/PPM image file formats

https://metacpan.org/release/Image-PBMlib

Perl5 module to determine the size of images in several common formats

https://metacpan.org/release/Image-Size

Import packages into other packages

http://search.cpan.org/dist/Import-Into/

Alternative but compatible interface to modules that export symbols

https://metacpan.org/release/Importer

Write Perl subroutines in other programming languages

https://metacpan.org/release/Inline

Multiple virtual files at the end of your code

https://metacpan.org/release/Inline-Files

Perl extension to convert to JSON (JavaScript Object Notation)

https://metacpan.org/release/JSON

Perl Wrapper Class for the various JSON classes

https://metacpan.org/release/JSON-Any

JSON converter that Does What I Want

https://metacpan.org/release/JSON-DWIW

Use Cpanel::JSON::XS with a fallback to JSON::PP

https://metacpan.org/release/JSON-MaybeXS

JSON::XS compatible pure-Perl module

https://metacpan.org/release/JSON-PP

Perl implementation of JSON-RPC 1.1 protocol

https://metacpan.org/release/JSON-RPC

JSON serialising/deserialising, done correctly and fast

https://metacpan.org/release/JSON-XS

Perl extension to convert to JSON (JavaScript Object Notation)

https://metacpan.org/release/JSON

Perl extension interface to convert Japanese text

https://metacpan.org/release/Jcode

Guess media type for a file or a URL

https://metacpan.org/release/LWP-MediaTypes