Apache::App::Mercury is a customizable, extensible customer to customer store and forward messaging application for Apache mod_perl. It uses a relational database (accessed via DBI) to store and retrieve messages, and uses CGI.pm to display them in standard HTML. Its design closely resembles a MVC design pattern, and it handles all message box navigation, message composition, sending, replying, etc.
Bare XML is a "bare" XML parser with all primary parsing done via a simple state engine with about 20 or so different states. A tree structure is created during parsing, with all node names and values linked via pointers directly into the original text buffer. As such, Bare XML is extremely fast and simple. Currently, the parser is available in a perl module with Perl glue to turn the created tree into a Perl hash tree. The module name is XML::Bare.
CGI::ContactForm is a Perl module that generates a contact form for the Web and sends a message to a predestinated recipient. Unlike many form-to-mail programs, it's limited to this single purpose, but it allows you to set up a decently designed form with a minimum of effort. In other words, it's simple to use rather than flexible, even if there are quite a few customization possibilities.
The CPAN shell (and module) automates or at least simplifies the building and installation of Perl modules and extensions. It includes some primitive searching capabilities and knows how to use Net::FTP, LWP, and certain external download clients to fetch distributions from the Internet. Then it automatically tests and installs them and their dependencies.
The CentralNic Toolkit is CentralNic's system for instantaneous Registry-Registrar Communications. Registrars can use this system to register and modify CentralNic domain names in real time, with no delays for human intervention or e-mail processing. The Toolkit also provides advanced and efficient methods for searching for and querying domain names and whois records, and retrieving account information.
Class::XPath is a Perl module which adds XPath-style matching to your object trees. This means that you can find nodes using an XPath-esque query with match() from anywhere in the tree. Also, the xpath() method returns a unique path to a given node which can be used as an identifier.