Perl is a free language, so to speak. It doesn't require anything special in the form of programming platforms, and that I believe that the whole open source bit is part of why it's growing in popularity.
in reply to Software piracy- what would you do?
Can you learn Perl without using the text/CD references? Certainly. I only wish that I had a site like this for my first time stumbling through Obj. Oriented C++. Books are forever, support the authors for the time & effort they put forth writing them.