Authen::Simple::WebForm is a Perl library for simple authentication against existing Web based forms using the Authen::Simple framework. This wraps up the LWP (libwww-perl) calls needed to attempt a login to a site that uses an HTML form for logins. It supports logins that require cookies, various form variables, special headers, multi-stage logins, and more.
Date::Calc::XS is a Perl module that is the C/XS part which Date::Calc used to consist of. Date::Calc has become a (pure-Perl) wrapper which tries to load Date::Calc::XS, and failing that, loads Date::Calc::PP (a pure-Perl implementation which is now part of Date::Calc and used to be Date::Pcalc).
File-Find-Object provides Perl programmers with an object-oriented alternative to the core File::Find module for traversing a directory structure, which has some serious interface limitations. As opposed to File::Find, File-Find-Object can be instantiated, can be interrupted in the middle, has an iterative interface, and can also return results as objects.
Perl::Critic is an extensible framework for creating and applying coding standards to Perl source code. Essentially, it is a static source code analysis engine. It is distributed with a number of Perl::Critic::Policy modules that attempt to enforce various coding guidelines. Most Policy modules are based on Damian Conway's book Perl Best Practices. However, Perl::Critic is not limited to PBP, and will even support Policies that contradict Conway. You can enable, disable, and customize those Polices through the Perl::Critic interface. You can also create new Policy modules that suit your own tastes.
Dexter is a tool that allows users to define extended attributes which can be associated with descriptors and editors. These attributes can be embedded into any well-formed XML document. The resulting embellished document, the 'source', is then input to the dexter engine. This will generate one or more XSLT stylesheets describing the input document interpolating editor modifications and any instructions specified by the descriptors. As dexter's operations are specified exclusively with extended attributes, all but the most unforgiving of XML content viewers will continue to see the decorated source exactly as the designer saw it before.
Coro is a package providing both low-level coroutines as well as a high-level multitasking abstraction on top of Perl. It allows you to parallelize LWP and other network protocols with ease. Unlike the so-called "Perl threads/fork emulation", they provide a real shared address space (like real threads) without the associated race conditions and performance loss, while maintaining a very low memory overhead (2-3kb/coroutine). The package comes with examples and many supporting modules.