DateTime is a class for the representation of date/time combinations. It represents the Gregorian calendar, extended backwards in time before its creation (in 1582).

Assigns a new name to referenced sub. If package specification is omitted in the name, then the current package is used. The return value is the sub.

XSLoader module defines a standard simplified interface to the dynamic linking mechanisms available on many platforms. Its primary purpose is to implement cheap automatic dynamic loading of Perl modules.

Atom is a syndication, API, and archiving format for weblogs and other data. XML::Atom implements the feed format as well as a client for the API.

Storable brings persistence to your Perl data structures containing SCALAR, ARRAY, HASH or REF objects, i.e. anything that can be conveniently stored to disk and retrieved at a later time.

This is pragma to change Perl 5's standard method resolution order from depth-first left-to-right (a.k.a - pre-order) to the more sophisticated C3 method resolution order.

Env::Path presents an object-oriented interface to path variables, defined as that subclass of environment variables which name an ordered list of file system elements separated by a platform-standard separator.

Text::CSV provides facilities for the composition and decomposition of comma-separated values. An instance of the Text::CSV class can combine fields into a CSV string and parse a CSV string into fields.

This module provides a general-purpose clone function to make deep copies of Perl data structures. It calls itself recursively to copy nested hash, array, scalar and reference types, including tied variables and objects.

Net::DBus provides a Perl XS API to the DBus inter-application messaging system. The Perl API covers the core base level of the DBus APIs, not concerning itself yet with the GLib or QT wrappers.

This package provides the Net::SNMP Perl module. It implements an object oriented interface to the Simple Network Management Protocol. Perl applications can use the module to retrieve or update information on a remote host using the SNMP protocol.

This module provides a facility for creating non-modifiable variables in Perl. This is useful for configuration files, headers, etc. It can also be useful as a development and debugging tool for catching updates to variables that should not be changed.

This module tries to provide a coherent API to bring together the various JSON modules currently on CPAN. This module will allow you to code to any JSON API and have it work regardless of which JSON module is actually installed.

Exporter implements an import method which allows a module to export functions and variables to its users' namespaces. Many modules use Exporter rather than implementing their own import method because Exporter provides a highly flexible interface, with an implementation optimised for the common case.

The Net::HTTP class is a low-level HTTP client. An instance of the Net::HTTP class represents a connection to an HTTP server. The HTTP protocol is described in RFC 2616. The Net::HTTP class supports HTTP/1.0 and HTTP/1.1.

XML::Feed is a syndication feed parser for both RSS and Atom feeds. It also implements feed auto-discovery for finding feeds, given a URI. XML::Feed supports the following syndication feed formats: RSS 0.91, RSS 1.0, RSS 2.0, Atom

This module finds URIs and URLs (according to what URI.pm considers a URI) in plain text. It only finds URIs which include a scheme (http:// or the like), for something a bit less strict, consider URI::Find::Schemeless. For a command-line interface, urifind is provided.

This module provides an interface to layout and image generation of directed and undirected graphs in a variety of formats (PostScript, PNG, etc.) using the dot, neato, twopi, circo, and fdp programs from the Graphviz project. This package is deprecated in favour of GraphViz2.

Net::PSYC with support for TCP, UDP, Event.pm, IO::Select and Gtk2 event loops. This package includes 12 applications and additional scripts: psycion (a PSYC chat client), remotor (a control console for tor router) and many more.

This module exports a single function: ttie. It ties a variable to a type constraint, ensuring that whatever values stored in the variable will conform to the type constraint. If the type constraint has coercions, these will be used if necessary to ensure values assigned to the variable conform.

Ref::Util introduces several functions to help identify references in a smarter (and usually faster) way. The difference with conventional approach:

• No comparison against a string constant

• Supports blessed variables

• Supports tied variables and magic

• Ignores overloading

• Ignores subtle types

• Usually faster

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 eases the writing of command line utilities, accepting commands and subcommands and so on. These commands can form a tree, which is mirrored in the package structure. On invocation, each command along the path through the tree (starting from the top-level command through to the most specific one) is instantiated.

The Inline::C module allows you to write Perl subroutines in C. Since version 0.30 the Inline module supports multiple programming languages and each language has its own support module. This document describes how to use Inline with the C programming language. It also goes a bit into Perl C internals.