I'd say that 80% of the Perl programs I've written in the past five years could be considered content management systems. The class of software that gets the "CMS" label is so varied that I'd be amazed if any working web developer hadn't written one! Pretty much anything that lets users edit stuff online that will later be viewed by a different class of users is plausibly a CMS.

Of course, if you're talking about monolithic works-for-everyone web-publishing systems, I've been there too. And, like the future governor of California says, I'll be back.

-sam