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.
DBIx-Class is an SQL to OO mapper with an object API inspired by Class::DBI (with a compatibility layer as a springboard for porting) and a resultset API that allows abstract encapsulation of database operations. It aims to make representing queries in your code as Perl-ish as possible while still providing access to as many of the capabilities of the database as possible, including retrieving related records from multiple tables in a single query.
Job-Machine is a small, but versatile system for sending jobs to a message queue and, if necessary, communicating answers back to the sender. Job::Machine uses LISTEN / NOTIFY from PostgreSQL to send signals between clients and workers. This ensures very efficient message passing, giving any worker that is awake the chance to start working immediately.
Libev is a high-performance event loop for C (with optional and separate interfaces for C++ and Perl), featuring support for I/O, timers (relative and absolute, cron-like ones), signals, process status changes, and other types of events. It has both a fast native API and libevent emulation to support programs written using the libevent API. Differences to libevent include higher speed, simpler design, more features, less memory usage, embedability, and no arbitrary limits. libev supports epoll, kqueue, Solaris event ports, poll, and select.