No, the hacker edition is available for everyone doing the course, though, those of us taking it through edx cannot submit the work done under the Hacker Edition for credit, we still can do it.
If your'e doing the edx one, under the courseware head, in the right bar, there are several weeks shown, just click any one of those weeks, and you'll see a section saying Problem Set 1(or whatever week your'e in) just like in the image below-

And click Problem set 1 will show you a change in the main column where you'll be shown what looks like this -

Now you can clearly see a Hacker Edition(optional) section under which are 2 heads, Specification's and HTML, clicking the HTML link would lead you to a webpage at cloud front.net, that is your desired link and here you'll find everything related to and about Hacker edition of the pset.
Happy Coding!