EventedObject is a simplistic yet highly useful Perl base class that allows you to attach event callbacks to an object (also known as a blessed hash reference) and then fire events on that object. Event fires are much like method calls. However, there can be many handlers, many return values, and many responses rather than just one of each. EventedObject is designed to be highly extensible and features callback priorities, dynamic adding and removing of callbacks, and more. It provides a whole new style of objective and event-driven programming in Perl.
PMilter implements Sendmail's "milter" mail filtering protocol in Perl, allowing scripts direct access to the SMTP transaction in progress, rather than filtering later. It can function as a drop-in replacement for Sendmail::Milter, though PMilter does not require threads or the "libmilter" API to be available.
TCB::Conference is a DBIx::Frame object written to track external registrants for the 2003 TCB Summer School. It provides external forms for registrants to apply with; internal scripts, for local users to track who has applied and what their status is; and administrative scripts for adding, modifying, or deleting this information. It was used for a single conference, but may be useful again.
TCB::Equipment is a DBIx::Frame object written to keep track of equipment and software at the Theoretical and Computational Biophysics Group at UIUC. It provides an administrative web interface for adding and managing equipment and software and sharing this information with the users. This is actually a fairly basic function of research groups, but doesn't have a standard software package.