Link to GPL version 3 from the homepage

ORGWEBPAGE/index.org

@@ -217,10 +217,12 @@ please go to [[http://orgmode.org/worg/][the Worg page]], and start from there.
 You can always contribute with ideas and bug reports on the mailing
 list.  If you want to contribute a patch, code snippets, or a full
 add-on, this is very welcome too!  We do distribute good add-ons as
-contributed packages.  However, to integrate additions into the
-Org-mode core, the author needs to assign the copyright to the [[http://www.fsf.org/][Free
-Software Foundation]].  This is because Org-mode is part of Emacs, which
-adheres to very strict rules.  If you would like to sign the papers,
-use [[file:request-assign-future.txt][this form]], fill it in and [[mailto:assign@gnu.org,carsten.dominik@gmail.com][send]] it to the FSF with a copy to the
-Org-mode maintainer.
+contributed packages under more-or-less arbitrary licenses.  However,
+to integrate additions into the Org-mode core, the author needs to
+assign the copyright to the [[http://www.fsf.org/][Free Software Foundation]].  This is because
+the Org-mode core is part of Emacs.  Emacs is distributed under the
+[[http://www.gnu.org/licenses/gpl.html][GNU Public License version 3]], and all packages included with it must
+do the same.  If you would like to sign the papers, use [[file:request-assign-future.txt][this form]],
+fill it in and [[mailto:assign@gnu.org,carsten.dominik@gmail.com][send]] it to the FSF with a copy to the Org-mode
+maintainer.