The reality is, it wasn't broken. It was trying to do a backtick call to the external formatter, which in this case was /usr/local/bin/markdown, which wasn't installed. The reality is, this is crap code with crap error detection. Doesn't use strict or warnings, and tries to badly reinvent what can be done with just a few perl modules. All good now, tho. And this post proves it. I'm using it now!