Sun Microsystems developed this file system called "ZFS," which is exceptionally awesome in it's capabilities and possibilities. The problem, is that it was developed and released as part of the Open Solaris project which has a licensing incompatibility with the Linux Kernel. Both are open source, but there is a technical (and not all together uncommon) conflict in the terms of the license that makes it possible to combine code from both licenses in a single executable.
Basically the GPL, under which the Linux Kernel is distributed, says if you distribute a binary (executable) under the terms of the GPL, the source code is all files that you used to make that binary. By contrast ZFS's license says "here are all the files that we used to make this binary, if you change them when you make your binary and give that binary to other people you have to give them, but if you add additional files, you don't have to give those out to people."
Apparently the idea behind the ZFS license (i.e. the CDDL, and the MPL from whence it originated,) is that it allows for easier embedding of ZFS (and other technologies) in proprietary code because the resulting binary isn't list covered by the CDDL in most cases. Even though the CDDL is incredibly confusing, apparently it's more "business friendly," but I diverge from my original point.
And so if Linux users want to run ZFS, they have to run it as a user-space process (i.e. not in the kernel,) which is suboptimal, or they have to run Solaris in a vitalized environment (difficult,) or something. There's also a ZFS-like file system called "btrfs," which can be included in the kernel (interestingly, developed by Oracle who of course now own ZFS itself,) but it is not production ready.
What I'm about to propose is an end run around the GPL. Because it seems to me that combining the source code violates neither license, distributing source code violates no license. Compiling the source code for your own use violates no license. I mean it's annoying and would require a bit of bootstrapping to get a Linux+zfs system up and running, but this is the kind of thing that Gentoo Linux users do all the time, and isn't a huge technological barrier.
It feels a bit creepy of course. but I think it works. The logic has also been used before. We'll call it the "PGP loophole."
PGP is an encryption system that's damn good so good in fact, that when it was first released, there were export restrictions on the source code because it qualified as military-grade munitions in America. Source code. How peculiar. In any case there were lawsuits, and PGP source was released outside of America by printing it in a book. Which could be disassembled and scanned into a computer and then compiled. Books were never and--as far as I know--are not classified as munitions, and so they could be exported. Of course I'm not a lawyer, but it strikes me that linux+zfs and PGP in the 90's may be in analogous situations.
And I think, because this proposal centers around the distribution of source code and only source code this kind of distribution is fully within the spirit of free software. Sure it's pretty easy, even for the "good guys," to run a foul by distributing a binary, but this would be easy to spot, and there are already suitable enforcement mechanisms in place, for the Linux kernel generally, and Oracle's legal department which we can assume will take care of itself.
Or Oracle could release ZFS under GPL. Either solution works for me.