A discussion on combining CDDL and GPL code

Posted May 30, 2016 21:02 UTC (Mon) by HsuYun (guest, #108980)
In reply to: A discussion on combining CDDL and GPL code by pboddie
Parent article: A discussion on combining CDDL and GPL code

Well, then use the MIT license for the binary. I still don't really get the problem. The GPL requires you to license both the code and binary of kernel modules to be under a compatible license. The only incompatibility of the CDDL is that you _could_ license the binary under a non-free license, but if you don't do that, you actually _do_ fulfill the requirements of the GPL that you can do everything with the module you could do with a GPL licensed module. Thinking about it this way, why is it ok to distribute an MIT licensed module with the kernel, because the MIT license would also allow you to license the binary under a non-free license. Where is the flaw in my thinking here?

A discussion on combining CDDL and GPL code

Posted May 30, 2016 21:56 UTC (Mon) by MattJD (subscriber, #91390) [Link]

That's not quite right, the GPL requires the entire worked to be licensed under the terms of the GPL. However, it is believed that the terms of the CDDL and the GPL are not compatible (not that the CDDL allows more, but that it has restrictions the GPL does not), and thus you can't distribute something under both licenses.

The MIT license is fine, because it allows you to distribute under basically any license (it's only restriction is basically a disclaimer, which the GPL shares in spirit (if not text), and thus imposes no further restrictions). Thus you can distribute something under the MIT license as GPL.

In both cases, what matters is that the non-GPL license imposes no more restrictions on the combined work. CDDL does, MIT doesn't.

Note: This is true for the GPL2 with Linux. Apparently the GPL3 is a little more muddy, but for the CDDL is still basically right.