Not covered in the article, but `rename` is a multi-file renamer. I wrote a script which used an `echo $f | sed | mv` loop before I learned about this.
This name clash makes that the perl module cannot be easily used on CentOS, since the CentOS utility is required for building RPM packages.
You'd have to edit Makefile.PL of the Perl module before installation, to avoid that clash. (I'd prefer to keep the name as "rename.pl", in this case; though file-rename, as on Windows, would work too.)