This is what the 0.2.1 setup says...
Date: December 01, 2000 04:21PM
"K-Meleon is licensed under the GNU General Public License (GPL).
The Gecko(tm) engine is subject to the Mozilla Public License license."
and then if you scroll down to the very bottom you get to a line that looks like this:
" 3.7. Larger Works.
You may create a Larger Work by combining Covered Code with other code
n"
the MPL ends in the middle of 3.7. I am not a lawyer, so I can't judge if this is an OK thing or not from a legal standpoint.