Since this project is getting a lot of attention lately, here are the license
terms (and let me know if it would be helpful to change them; I'm flexible):

The Perl object is licensed however it needs to be licensed to stay legal
considering that it uses the GNU readline Perl module. But nobody's going to be
using the Perl object anyway, so I suspect this doesn't matter.

The TeX file and PDF are licensed under the MIT license or
/L?GPL v[23](\.\d+)?/. This means it's totally OK to:

  1. Create a modified version (it would be cool if it were obviously marked
     as being modified).
  2. Convert the guide to another language, such as Ruby.
  3. Fix errors, bugs, or misleading segments, publicly complain about the fact
     that they were there in the first place, and then issue a pull request.
     (Though commenting on a commit is usually all it takes :) )

By the way, this PDF is way longer than ten minutes, despite what the title
says. The ten-minute version was probably back at commit
c5bbb1d47ea472b445373a26ab19c98173508420 or so.