I hope, after you got this answered, you remain here to learn some bit more.

As side note to what stevieb already said, I suggest you to NOT use the system Perl you have already installed on the machine.

First the system Perl you have is 5.8.4 ie a grand-grand-mother release of July 2004.

Second, and more important: tomorrow your developper needs Some::Module so you go to install it. It happens that Some::Module has as requisite Another::Module with minimal version x.y but your system has Another::Module version u.v so you upgrade it and it might happens that your system Perl becomes buggy. Not always the story is that bad, but it can happen. So play safe.

It is very easy to have multiple perl installation on the same machine: just install into another directory and dont mess with the PERL5LIB env var. You can do a link to the new perl and tell the dev to use it.

Laziest ones can also use perlbrew to manage several installations of Perl. But in your case is a bit overkilling.

Doing this you can offer a modern Perl release to your dev, currently 5.24 with all modules at the last release.

For your reference take a look to following posts: