CPAN modules are normally distributed with Makefile.PL or Build.PL, so that people can install them by > perl Makefile.PL > make > make test > make install This makes CPAN modules installable without any CPAN clients help unlike other programing language ecosystem (such as ruby(gem), node(npm)). On the other hand, today, people mostly use CPAN clients (such as CPAN.pm, cpanm) to install CPAN modul