&gt; There are people, though, that when looking for a license to use when releasing their software specifically choose one that is known to be incompatible with the GPL.<p>The issue at hand is <i>not</i> that the CDDL licensed software is being re-distributed under a GPL license. It&#x27;s not. The issue is whether or not GPL software and CDDL software can interact in such a way as to violate the GPL license.<p>I doubt very much that &quot;this can&#x27;t be ported to a Linux kernel module&quot; was a deciding factor when choosing the CDDL. If it <i>was</i> such an important factor, then they should have modified the CDDL to add such language to the license, which would make this issue <i>much</i> more clear.