Amethyst started as a port of Infobot to POE, continuing as a generic bot core with the ability to handle multiple connections using different protocols (not necessarily IRC) and soft route the incoming messages through a number of processing centres. One of these processing centres contains much of the original Infobot core.
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.
dkimproxy is an SMTP proxy that signs and/or verifies Domain Keys Identified Mail (DKIM). It is designed to work with Postfix. It comprises two separate proxies: an "outbound" proxy for signing outgoing email, and an "inbound" proxy for verifying signatures of incoming email. With Postfix, the proxies can operate as either Before-Queue or After-Queue content filters.
Dkfilter is a DomainKeys implementation for the Postfix mail transfer agent. It is implemented as two filters (or SMTP proxies). There is an "outbound" filter for adding DomainKeys signatures to outgoing email and an "inbound" filter for verifying signatures of incoming email. The filters can be plugged into Postfix as either Before-Queue or After-Queue Postfix content filters. For more information about DomainKeys, see http://antispam.yahoo.com/domainkeys.
Huntor is a full-featured command line Bittorrent client. It currently has no GUI. This client focuses on being run in the background, such as on servers. It is highly customizable. Its disk storage layout makes it easy to incrementally rsync the data to a different machine while downloading.
JSON::XS implements JSON for Perl. Unlike other modules, its primary goal is to encode to syntactically correct JSON and flag invalid JSON while decoding. It ensures round-trip integrity of data types while being intuitive to use. Currently being the fastest of the JSON encoders available for Perl, it supports a variety of format options, such as single-line, ASCII-only, or pretty-printed, and can be tuned for speed or memory usage. It comes with a wealth of documentation describing usage and implementation details.