> You know, including the sources of perl libraries you use just to make some changes in them...

Pretty much the only external library that is included is MIME::Base64. This is because it's not in all default installs, and most people can't install external libraries. A lot of other code is written from scratch, but duplicates functionality that exist in third-party modules, but since lots of people can't install those, I can't use them if I want people to be able to use the script.