The Common Development and Distribution License [LWN.net]

Sun has submitted a new license (the "Common Development and Distribution License" or CDDL) to the Open Source Initiative's license-discuss mailing list. This license, derived from the Mozilla Public License, may (or may not) be what Sun chooses to use for its possible open-source Solaris release, so it is worth a look.

This license is GPL-like in its intent, but (as Sun acknowledges up front) it is not compatible with the GPL. There are certain extra terms in the CDDL which, while not necessarily objectionable in their own right, conflict with the GPL's "no additional restrictions" terms. This incompatibility came as a surprise to few people; nobody has ever expected Sun to encourage the mixing of Solaris and Linux kernel code.

The CDDL licenses the copyrights in the code for use, distribution, and modification - the usual free software rights. It also contains a patent grant, but here the language is a bit more constrained:

(b) under Patent Claims infringed by the making, using or selling of Original Software, to make, have made, use, practice, sell, and offer for sale, and/or otherwise dispose of the Original Software (or portions thereof).

In other words, the CDDL does not license any patents for use in derived products. Other terms in the license suggest that Sun is concerned about patent infringements caused by modifications, but the above exclusion is not restricted to such infringements.

The license requires that anybody distributing the code in binary form make the associated source available under the CDDL. The license says nothing about how the source must be made available; in theory, one could satisfy the license by requiring people to pick up the source in person at one's Mongolian software distribution center. Interestingly, the license allows the binaries themselves to be distributed under any license, so long as (1) the source is available under the CDDL, and (2) the person distributing binaries under a different license indemnifies the copyright holders for any liabilities.

Unlike the GPL, the CDDL allows developers to make modifications to the license text itself (for their own code).

The CDDL contains patent defense language: if you sue a copyright holder for patent infringement, you can lose your rights to use the code under the license. In any patent litigation settlement talks, the value of the patent license granted by the CDDL must be taken into account - essentially, the party initiating the lawsuit loses any patent license granted by the CDDL. There is one other strange term:

6.4. In the event of termination under Sections 6.1 or 6.2 above, all end user licenses (excluding distributors and resellers) that have been validly granted by You or any distributor hereunder prior to termination (excluding licenses granted to You by any distributor) shall survive termination.

So if you are a software distributor, and you got the code from somebody who later turns around and sues Sun, you can lose your rights to the software under the license.

The discussion has been relatively muted; there seems to be an early consensus that the license, possibly with some small tweaks, is, indeed, a free software license. It will probably get the stamp of approval that Sun seeks. What Sun will then do with this license remains to be seen, however.

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The Common Development and Distribution License

Posted Dec 9, 2004 7:05 UTC (Thu) by piman (guest, #8957) [Link] (2 responses)

> 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.

The Common Development and Distribution License

Posted Dec 9, 2004 17:15 UTC (Thu) by iabervon (subscriber, #722) [Link] (1 responses)

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.

The Common Development and Distribution License

Posted Dec 9, 2004 9:36 UTC (Thu) by mfrancis (subscriber, #14996) [Link] (3 responses)

> > 6.4. In the event of termination under Sections 6.1 or 6.2 above, all end user licenses [...] shall survive termination.

Surely this means the opposite of

> So if you are a software distributor, and you got the code from somebody who later turns around and sues Sun, you can lose your rights to the software under the license.

And in fact Sun are guaranteeing that this will not happen ?

The Common Development and Distribution License

Posted Dec 9, 2004 10:02 UTC (Thu) by james (guest, #1325) [Link] (1 responses)

...end user licenses (excluding distributors and resellers)...

So if you're an end-user, you're fine.

But it explicitly excludes distributors and resellers, with the implication that their licenses will be revoked.

Section 6.1 is "if you fail to comply with the terms" and 6.2 is "don't sue us for patents".

So if, hypothetically, Sun's good friend Microsoft were to make a CDDL-licensed Solaris Media Player, based on XML code that Sun had licensed, there would be nothing to stop Red Hat or SUSE including it in their distributions.

But then if Sun and Microsoft fell out again (as seems plausible) and Microsoft sued Sun for patent infringement over XML...

Sun would be the Initial Developer, Microsoft would be the party whose license rights were revoked. Red Hat's and SUSE's end-users would be protected by the above clause, but Red Hat and SUSE, as distributors and resellers, might not be.

James.

Chain license termination

Posted Dec 10, 2004 1:32 UTC (Fri) by giraffedata (guest, #1954) [Link]

it explicitly excludes distributors and resellers, with the implication that their licenses will be revoked.

But such implications have no legal impact, so I wonder if there's something else in the license that says all downstream licenses are conditional on the behavior of the distributor.

The Common Development and Distribution License

Posted Dec 10, 2004 18:38 UTC (Fri) by garloff (subscriber, #319) [Link]

Indeed, it does mean the opposite.

And if you look at the reasoning why the Munich court held the GPL
valid, you'll understand why this clause was put there.