The Common Development and Distribution License [LWN.net]

The Common Development and Distribution License

Posted Dec 9, 2004 7:05 UTC (Thu) by piman (subscriber, #8957)
Parent article: The Common Development and Distribution License

> Unlike the GPL, the CDDL allows developers to make modifications to the license text itself.

This is slightly misleading. The unmodifiable part of the GPL is the preamble, which is not technically a term of the license; one can make a license equivalent to the GPL in its terms (and so compatible with the GPL), but use only free license text. See http://www.gnu.org/licenses/gpl-faq.html#ModifyGPL for more information.

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The Common Development and Distribution License

Posted Dec 9, 2004 17:15 UTC (Thu) by iabervon (subscriber, #722) [Link]

That seems to me to refer to making a new license which includes samples from the GPL, not taking the GPL document and clarifying your interpretations of the terms. Also, I can't see any reason to believe the GPL FAQ's idea of what you can do with the terms, aside from the fact that the FAQ is a written document from the owner of the GPL document, so it would probably be considered permission for anything it permits, even if those things wouldn't be permitted otherwise. The GPL document itself states: "Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed."

Of course, copyright not being patents, you can certainly reverse-engineer the GPL and produce a free equivalent.

The Common Development and Distribution License

Posted Dec 9, 2004 18:31 UTC (Thu) by JoeBuck (subscriber, #2330) [Link]

The differences really don't matter much in practice. Sun's license allows modifications only if the modified license has a new name and no references to Sun (other than a notice that the new licence differs from the CDDL). The GPL text itself can't be changed, but a derived license can be created by including the GPL file in a distribution, and then saying that the license that applies to the work is the GPL together with a set of modifications. It seems that language like Sun's is the minimum necessary to prevent fraud; if a license text can be modified without restriction, this could be used to fool people into accepting terms they disagree with (just insert a strategic "not" somewhere).

The only sense in which the difference matters is that if the GPL is altered in this way, the original text of the GPL has to be included in full, which offends some people who don't like the condemnation of proprietary software in the GPL's preamble.