G'day carlriz,

If you'd actually named the Perl module, I could provide a more specific answer.

A Perl module is written in Perl. This is not what you're looking at. As an example, look at the source code for Data::Dumper (which I just picked at random).

What you've posted is the source code used to generate a manpage. The equivalent code for Data::Dumper starts like this:

.\" Automatically generated by Pod::Man 2.27 (Pod::Simple 3.28)
.\"
.\" Standard preamble:
.\" ==================================================================
+======
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
[download]

As you can see on the first line, this is "generated by Pod::Man". See the Pod::Man documentation for more information (if you're still interested).