Tie::EncryptedHash augments Perl hash semantics to build secure, encrypting containers of data. Tie::EncryptedHash introduces special hash fields that are coupled with encrypt/decrypt routines to encrypt assignments at STORE() and decrypt retrievals at FETCH(). Encryption is done with Blowfish, DES, or IDEA.
The IPC::SharedCache Perl module provides a shared-memory cache accessed as a tied hash. Shared memory is an area of memory that is available to all processes. It is accessed by choosing a key. Every process that accesses shared memory with the same key gets access to the same region of memory. This module attempts to make shared memory easy to use for one specific application -- a shared memory cache.
News::Overview is a Perl object that manages condensed information about Usenet posts in the overview format. It accepts information from an NNTP XOVER command, and allows for basic searching and sorting of the referenced articles. It was designed to be part of several other news modules.
find_used_modules looks over your entire system and figures out which modules people are using. It then builds a Perl script that can be used to test to make sure that all those modules are available. The purpose of all this is to allow Perl to be upgraded without breaking too many installed Perl programs.