Another misconception that needs to be addressed is that Thing.pm does not necessarily have very much to do with Thing::OtherThing or Thing::Simple or Thing::Whatever in each of those cases you have a module called OtherThing.pm or Simple.pm or Whatever.pm in a folder called "/Thing". These modules may or may not require you to have Thing.pm installed. I don't see CGI::Simple in my standard distribution, so I doubt that it is supported by the creator of CGI.pm. My best advice to you is to read the documentation for CGI.pm and for CGI::Simple, and use whichever makes sense to you.