JoeDog::Config
I use this module all the time. If I had more clout, it would be part of perl. Sadly, I have no clout but that doesn’t mean it can’t be an indispensible part of your toolkit. JoeDog::Config parses configuration files and stores the data in perl data structures. It reads columns, key-value pairs, and INI style config files into arrays, hashes and hashes of hashes. It can take characters or regexes for separators. The module is well documented and very easy to use. If you’re not used to using a hash of hashes or an array of arrays, don’t worry. The documention shows you how to use those data structures.
* UNIX tarball
* Windows zip

JoeDog::Stats
A perl module that performs descriptive statistical analyses on grouped or ungrouped data provided by arrays, hashes or frequency distributions. Frequency distributions can be saved to file and loaded later. These files require a fraction of disk space compared to the original data. They are perfect for long-term storage and analysis.
* UNIX tarball
* Windows zip

JoeDog::Plock
A perl extension that helps ensure there is only one running copy of your script. In most usecases, flock will work just fine for this. Unfortunately, that function is buggy on linux NFS shares. JoeDog::Plock uses a local socket as a locking mechanism. Plock == Port lock.
* UNIX tarball
* Windows zip 
* RedHat RPM

JoeDog::ProgressBar
A perl extension that provides an ASCII progress bar for your perl scripts. You can run it inside any loop for which you can calculate the last iteration.  It’s simple to use and easy to impress your co-workers.

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* UNIX tarball
* Windows zip 

JoeDog::Wacky
A perl mondule that implements the WACKY/1.0 protocol. It allows you to manipulate the keyboard lights on any computer running Wackyd.
* UNIX tarball
* Windows zip