Re: bbPress mobile version
Alex’s SVN links here:
https://plugins.trac.wordpress.org/browser/wordpress-mobile-edition/trunk/wp-mobile.php
Lines 17 and 18 mention a GPL license:
17 // Released under the GPL license
18 // http://www.opensource.org/licenses/gpl-license.php
So you should definitely be able to release this plugin as a derivative work. Good thing too, b/c I’d love to use it! 
