__DIR__ constant for the directory your source file is in

https://metacpan.org/release/Dir-Self

Declare version conflicts for your dist

https://metacpan.org/release/Dist-CheckConflicts

Deconstructed dynamic C library loading

https://metacpan.org/release/DynaLoader-Functions

Perl interface to libev, a high performance full-featured event loop

https://metacpan.org/release/EV

Unified interface to mail representations

https://metacpan.org/release/Email-Abstract

RFC 2822 Address Parsing and Creation

https://metacpan.org/release/Email-Address

Parse and format RFC 2822 email addresses and groups

https://metacpan.org/release/Email-Address-XS

Produce RFC 2822 date strings

https://metacpan.org/release/Email-Date-Format

Easy MIME message parsing

https://metacpan.org/release/Email-MIME

Parse a MIME Content-Type Header

https://metacpan.org/release/Email-MIME-ContentType

Unified interface to MIME encoding and decoding

https://metacpan.org/release/Email-MIME-Encodings

Modify Email::MIME Objects Easily

http://search.cpan.org/dist/Email-MIME-Modifier/

Generate world unique message-ids

https://metacpan.org/release/Email-MessageID

Read e-mail messages stored as .msg files

https://metacpan.org/release/Email-Outlook-Message

Perl module for simple email sending

https://metacpan.org/release/Email-Send

Library for sending email

https://metacpan.org/release/Email-Sender

Simple parsing of RFC2822 message format and headers

https://metacpan.org/release/Email-Simple

More casual approach to creating and sending Email

https://metacpan.org/release/Email-Stuffer

Provides interfaces between strings and the rest of the system

https://metacpan.org/release/Encode

Encode::Encoding subclass that detects the encoding of data

https://metacpan.org/release/Encode-Detect

Traditional and Simplified Chinese mappings

https://metacpan.org/release/Encode-HanConvert

Extra sets of Chinese encodings

https://metacpan.org/release/Encode-HanExtra

JIS X 0212 (aka JIS 2000) Encodings

https://metacpan.org/release/Encode-JIS2K

Determine the locale encoding

https://metacpan.org/release/Encode-Locale

Error/exception handling in object-oriented programming style

https://metacpan.org/release/Error

Safely and cleanly create closures via string eval

https://metacpan.org/release/Eval-Closure

Real exception classes in Perl

https://metacpan.org/release/Exception-Class

Lightweight exporting of functions and variables

https://metacpan.org/pod/Exporter::Lite

Exporter with features of Sub::Exporter but only core dependencies

https://metacpan.org/release/Exporter-Tiny

Compile and link C code for Perl modules

https://metacpan.org/release/ExtUtils-CBuilder

Configure-time utilities for using C headers, libraries, OS features

https://metacpan.org/release/ExtUtils-CChecker

Wrapper for perl configuration

https://metacpan.org/release/ExtUtils-Config

Easily build XS extensions that depend on XS extensions

https://metacpan.org/release/ExtUtils-Depends

Various portability utilities for module builders

https://metacpan.org/release/ExtUtils-Helpers

Build.PL install path logic made easy

https://metacpan.org/release/ExtUtils-InstallPaths

Designed to write a Makefile for an extension module

https://metacpan.org/release/ExtUtils-MakeMaker

Cpanfile support for ExtUtils::MakeMaker

https://metacpan.org/release/ExtUtils-MakeMaker-CPANfile

Converts Perl XS code into C code

https://metacpan.org/release/ExtUtils-ParseXS

Simplistic interface to pkg-config

https://metacpan.org/release/ExtUtils-PkgConfig

Autogenerating XS-glue Code

https://metacpan.org/release/ExtUtils-XSBuilder

Modules for perl5, for enabling FastCGI support in CGI scripts

https://metacpan.org/release/FCGI

Functions for managing FastCGI applications

https://metacpan.org/release/FCGI-ProcManager

Perl extension for recursively copying files and directories

https://metacpan.org/release/File-Copy-Recursive

Recursive copying of files and directories

https://metacpan.org/release/File-Copy-Recursive-Reduced

Object oriented File::Find replacement

https://metacpan.org/release/File-Find-Object

Alternative interface to File::Find

https://metacpan.org/release/File-Find-Rule

Common rules for searching for Perl things

https://metacpan.org/release/File-Find-Rule-Perl

Get home directory for self or other users

https://metacpan.org/release/File-HomeDir

Parse directory listings

https://metacpan.org/release/File-Listing

File::NFSLock - perl module to do NFS (or not) locking

https://metacpan.org/release/File-NFSLock