On 04/27/2015 12:28 PM, Joerg Schilling wrote: > Up to now, nobody could explain me how a mixture of GPL and BSD can be legal as > this would require (when following the GPL) to relicense the BSD code under GPL > in order to make the whole be under GPL. The GPL doesn't require that you relicense any non-GPL parts of the whole. It requires that the whole "be licensed ... at no charge to all third parties under the terms of this License" The whole, containing portions which are BSD licensed, does not place any additional restrictions or responsibilities upon recipients, and therefore satisfies the requirements of GPL2 section 2.b. > In other words, if you can legally combine BSD code with GPL code, you can do > with GPL and CDDL as well. No, you can't. Section 6 of the GPL states that "You may not impose any further restrictions on the recipients' exercise of the rights granted herein." CDDL however, does contain additional restrictions. Moreover, the exclusion is mutual. Section 3.4 of the CDDL states "You may not offer or impose any terms on any Covered Software in Source Code form that alters or restricts the applicable version of this License or the recipients' rights hereunder." The GPL2 restricts the recipients rights in ways that the CDDL does not. I'm not able to find any information about actual court decisions about compatibility between GPL 2 or 3 and CDDL or MPL 1.1 (upon which CDDL was based). The FSF regards MPL 1.1 and CDDL as incompatible with GPL. If you and your lawyers disagree, you might end up as the first to establish a court precedent. Only you can decide for yourself if that is a risk you would like to undertake, and if the value of testing that notion is worth the costs. Until then, any claim that the two are compatible is naive.