Perl developers are used to using POD rather than some other code documentation tools. However, most developers are not restricted to using a single language. Instead of using multiple code documentation systems one tends to use one tool for all - Doxygen is quite a powerful code documentation system that already has built-in support for multiple programming languages.
Unfortunately, Doxygen does not directly support Perl. Thus, Doxygen Filter has been written in order to be able to use Doxygen for generating code documentation for Perl projects, too.