For the longest time (too long really), I hadn't really bothered to learn much about how to use XML, nor had I made the leap into using XML. In the past few months, that situation has changed dramatically.
After spending the time to figure out how to use XML, and where to use XML, I use it all over the place. All the config files I write for perl apps are written in XML. I've even gone back and rewritten perl apps that functioned just fine (for years, in some cases) just because the apps did not use XML and they seemed so clumsy without it. Today, I went crazy with XML-RPC. I'd been hearing about that technology for some time, but had never had reason or time to figure out how to use it or why I might want to use it.
Replacing perl apps that called each other via basic CGI calls with perl apps that use XML-RPC was a brain-dead decision. In fact, the apps got significantly easier to write and understand once I dumped the kludgy CGI interconnection and moved strictly to XML-RPC.
If you need a quick and easy way to connect several disparate perl apps (even ones running on different platforms), I suggest taking a look at XML-RPC.