A recent thread on the lkml discussed a blog entry stating that minimal ZFS support for GRUB was available under the GPL license, "we could now use that code to implement support for ZFS in the Linux kernel." Alan Cox explained, "no we can't. The GPL ZFS bits don't include the various methods that would violate the patent so there is no grant. I've several times asked Sun to simply give permission and they don't even answer. I can only read the Sun motivation one way - they want to look open but know that ZFS is about the only thing that might save Solaris as a product in the data centre so are not truly prepared to let Linus use it." H. Peter Anvin added, "from what I can see, it is an absolutely-minimal read only implementation."
Christoph Hellwig offered, "adding a read-only for the start zfs driver for Linux would be useful for various purposes. And adding read-only filesystems to Linux is really easy." Referring to the individual who started the discussion, he added, "if Fred really cares about it I'd be very happy to mentor him implementing it. It should be a very good learning exercise for him." When asked if this offer applied to anyone else, Christoph replied, "yes, this offer is of course up to everyone interested. But it's not purely an integration effort in the traditional sense, the grub filesystem interface is quite different from the Linux one, and the code structure and style is quite different. But if you're willing to learn it should be very interesting."
"It is kind of strange to us to have Sun suddenly be the perfect example of openness."
"I was impressed in the sense that it was a hell of a lot better than the disaster that were the earlier drafts," Linus Torvalds explained in reply to a comment suggesting that he was impressed with the final draft of the GPLv3. He went on to add, "I still think GPLv2 is simply the better license." The discussion began with a suggestion that the Linux kernel be dual-licensed GPLv2 and GPLv3. Linus noted, "I consider dual-licensing unlikely (and technically quite hard), but at least _possible_ in theory. I have yet to see any actual *reasons* for licensing under the GPLv3, though. All I've heard are shrill voices about 'tivoization' (which I expressly think is ok) and panicked worries about Novell-MS (which seems way overblown, and quite frankly, the argument seems to not so much be about the Novell deal, as about an excuse to push the GPLv3)." In a followup email, Linus added:
"Btw, if Sun really _is_ going to release OpenSolaris under GPLv3, that _may_ be a good reason. I don't think the GPLv3 is as good a license as v2, but on the other hand, I'm pragmatic, and if we can avoid having two kernels with two different licenses and the friction that causes, I at least see the _reason_ for GPLv3. As it is, I don't really see a reason at all."
A recent discussion on the lkml examined the possibility of a Linux implementation of Sun's ZFS. It was pointed out that the file system is released under the GPL-incompatible CDDL, and that Sun has filed numerous patents to prevent ZFS from being reverse engineered. Max Yudin pointed out, "according to Jeff Bonwick's blog Sun issued 56 patents on ZFS, but I have no idea what they patented. Sorry, binary compatible ZFS reimplementation with GPL license might not be legal." David Litwin noted that he had been told by a ZFS developer to talk to Linux developers to see about getting non-GPL'd code included with the kernel. Theodore T'so replied, "that was totally useless answer from the ZFS developers. What he should have told you is to contact Sun management, since they are the only ones who can decide whether or not to release ZFS under a GPL license, and more importantly, to give a patent license for any patents they may have filed in the course of developing ZFS."
Alan Cox [interview] suggested, "the real test of whether Sun were serious about ZFS being anywhere but Solaris is what they do to license it - they've patented everything they can, and made the code available only under licenses incompatible with other OS products. Their intent is quite clear, and quite sad. Compare it to what the old Sun company did with NFS, which is now a standard used everywhere." Theodore T'so added, "given that Sun has reportedly filed a huge number of patents covering ZFS and has refused to make them available for anything other than Solaris --- and there are senior Sun programmers who have on record stated that one of the reasons why Sun picked the CDDL was precisely because it was incompatible with GPL and Sun fears Linux ---- I wouldn't bet on Sun being willing to making a patent license available to a hypothetical alternate implementation of the ZFS format for Linux." He went on to note, "of course, this is all open source. If someone wants to work on reimplementing ZFS from scratch, either in userspace or in the kernel, certainly the Linux community won't stop them. Given the patent issues Linus might not feel comfortable including it in the mainline sources without a promise from Sun that they won't sue the pants off of him and The Linux Foundation, but again, that's Sun's decision, and no one else can help you there."
Greg Kroah-Hartman's announcement for free Linux driver development [story] included the necesssary legal framework to honor NDAs when creating GPL'd drivers. This allowance was discussed on the OpenBSD -misc mailing list. In a public exchange with Greg KH, Stephan Rickauer said, "now these companies have a great excuse to keep specs locked up tight under NDA, while pretending to be 'open.' The OpenBSD project has made clear more than once how this will hurt Free Software in the long run. Signing NDA's ensures that Linux gets a working driver, sure, but the internals are indistinguishable from magic. It is a source code version of a blob." OpenBSD founder Theo de Raadt [interview] called the free driver effort a farce, "you are trying to make sure that maintainers of code -- ie. any random joe who wants to improve the code in the future -- has LESS ACCESS to docs later on because someone signed an NDA to write it in the first place. You are making a very big mistake."
Greg pointed the discussion to his FAQ in which the final question asks about the BSD operating systems and the answer states, "what about them? They are free to do whatever they wish, I have no input into their development at all, sorry." Greg further clarified, "well, as my goal is to have a GPL driver for everything, I don't see how this can hurt :) Now others can have different goals, and that's great and fine. I'm not saying you can't work on something if you wish to do so."
