Aggregate of GPL and CPAL?

Chuck Swiger chuck at
Tue Mar 8 20:19:37 UTC 2011

On Mar 8, 2011, at 11:46 AM, Victor Mataré wrote:
> I'm trying to find out if I can bundle my GPLv3 product with a third-party product which uses CPAL 1.0.

Are you the sole author/copyright holder of the GPLv3 software?  If so, then you can (and would need to) grant an exception to the GPL terms to be miscible with the CPAL software.

> I'm pretty sure I'm not creating a derived work since I'm not subclassing or modifying anything. I'm only instantiating a couple classes from the CPAL software in my GPLv3 piece.

As far as the FSF is concerned, simply linking the two together is enough to create a derived work, although other people find that debatable.  Please see

"Common Public Attribution License 1.0 (CPAL)
This is a free software license.  It is based on the Mozilla Public License, and is incompatible with the GPL for the same reasons: it has several requirements for modified versions that do not exist in the GPL. It also requires you to publish the source of the program if you allow others to use it."
[ ... ]
"Mozilla Public License (MPL)
This is a free software license which is not a strong copyleft; unlike the X11 license, it has some complex restrictions that make it incompatible with the GNU GPL. That is, a module covered by the GPL and a module covered by the MPL cannot legally be linked together. We urge you not to use the MPL for this reason.

However, MPL 1.1 has a provision (section 13) that allows a program (or parts of it) to offer a choice of another license as well. If part of a program allows the GNU GPL as an alternate choice, or any other GPL-compatible license as an alternate choice, that part of the program has a GPL-compatible license."


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