<i>The kernel is built with APIs for the attachment of modules---which in a user space program might be called &quot;plug-ins&quot;---which can be statically linked with the kernel or dynamically loaded into kernel space by a running kernel. As with any such interface in a GPLv2 program running outside kernel space, we can assume that within kernel space the overwhelming preponderance of such modules or plug-ins can be assumed to fall within the scope of the copyleft on the kernel.</i><p>I don&#x27;t think I&#x27;m understanding this passage correctly.  Or if I am understanding it correctly, I&#x27;m not sure I see the logic.  How is this passage intended to be interpreted?<p>I think it&#x27;s saying that if a user space program has an API that allows plugins to be written, the plugins should be considered derivative works of the main program.  Thus if the main program is distributed under a standard copyright, any 3rd-party plugin is copyright infringing in the absence of specific licensing to allow it.<p>Is this true?  If anyone would know it would be Eben, but this seems at odds with the purpose of such an API.  On the other hand, &quot;As with any such interface ... we can assume ... that the overwhelming preponderance ... can be assumed to fall within the scope of the copyleft&quot; doesn&#x27;t sound like the sort of precise legal prose Eben normally writes.