&gt; his opinion should carry a lot of weight<p>That&#x27;s nice, but it&#x27;s only one side.  What about the opinion of the developers who wrote the module and licensed it under CDDL?<p>The incompatibility between CDDL and GPL is well-known, and the authors at Sun made it that way deliberately.<p>It&#x27;s not kosher to just say, &quot;Well the authors of the GPL software are okay with it, so it&#x27;s fine.&quot;  You need to respect the wishes of the developers who contributed the CDDL code to begin with.