Berkeley DB XML is a native XML database engine for use within your product. Made available as a C++ library with language bindings for Java, Perl, Python, PHP, and Tcl, it integrates directly into your application (it is not a standalone database server). It provides XQuery access into a database of document containers. XML documents are stored and indexed in their native format using Berkeley DB as the transactional database engine.
ORMesque is an object relational mapper for the Dancer framework that provides a database connection to the database of your choice and automatically creates objects and accessors for that database and its tables and columns. It uses the SQL::Abstract querying syntax, and can also be used as a standalone ORM. It is a great alternative when you don't have the time, need, or desire to learn DBIx::Class.
The Tcl extension provides a small but complete interface into libtcl and any other Tcl-based library for Perl programmers. It lets you create Tcl interpreters (as Perl 5 objects), bind in commands to them (either Perl subroutines or C functions dynamically loaded with the DynaLoader extension), and execute Tcl code in those interpreters.
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.
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.