Perlbal is a Perl-based reverse proxy load balancer and Web server. It processes hundreds of millions of requests a day just for LiveJournal, Vox, and TypePad, and dozens of other "Web 2.0" applications. One of the defining things about Perlbal is that almost everything can be configured or reconfigured on the fly without needing to restart the software.
Chart::Clicker aims to be a powerful, extensible charting Perl package that creates really pretty output. Charts can be saved in PNG, SVG, PDF, and PostScript format. Clicker leverages the power of Graphics::Primitive to create snazzy graphics without being tied to a specific backend.
C-DynaLib is a Perl module that allows Perl programs to call C functions in dynamic libraries. It is useful for testing library functions, writing simple programs without the bother of XS, and generating C function pointers that call Perl code. If you have a C compiler that Perl supports, you will get better results by writing XSubs than by using this module.
Robotics::IRobot provides a Perl interface for controlling and accessing sensor data from iRobot robots that support the OI Interface. It allows for both event-driven and polling-based reading of sensor data. It provides all functionality defined in the OI Interface for Roomba 400 series and Create robots. Also provided is some additional functionality such as primative dead reckoning and enhanced use of the Create's song functionality.