Sorry, this is a 'newbe' question.

Hi, my name is Alec Aakesson, and I just moved from linux/freebsd environment to a Mac environment. I would like to download the darwin ports and install them on my Mac [OS X 10.4]. I would like to know if I have to pay to do that or buy any special software? Is it available to any one? I am not doing this for any organization, but for my own edification. When I went to download the source for the ports I was asked to enter my 'work e-mail address.' I am used to working with freebsd ports, but I am not quite sure how Mac does things. Please let me know. Cheers, Alec -- "Every day it rains, its Tuesday."