Hi t3g
ZFS is not a probelm of being right or wrong. It is about license.
As any other software, unless it is under public domain, ZFS comes with a
license, a license which is called
Common Development and Distribution License (CDDL)
Now, GNU/Linux is an Operative system with a license called:
GNU General Public License (GPL).
This two licenses are legal documents, that tell you how can you use the
software, and what happens if you distribute the software. Both are free
software licenses BUT (and this is really important) that doesn't mean they
are compatible.
This is because the CDDL was intentionally written in a way that wouldn't be
compatible with GNU GPL. Which means that if GNU/Linux or Trisquel or even
Debian or Ubuntu include software under a CDDL license they could be in
legal trouble.
Now Ubuntu and Debian and many other distributions don't care and are willing
to take that risk. Maybe nothing would happen. But that does not mean that
they are doing something legal.
If you are interested in why they are not compatible it is because GPL has a
strong copyleft, so If i write a program with a GPL license and someone else
uses my code and does another program, it has to be under GPL too, it
doesn't matter if my program is changed by 20 diferent people, all the 20
versions of the program will be under GPL.
In the other hand CDDL has a weak copyleft, so it respects less the users
freedom. Because only the source code is free, but not other files, like the
art. (This licence was based on Mozilla Public Licence MPL, the license used
by Firefox and Thunderbird. The MPL is the reason why many distributions use
IceCat, Iceweasel or Abrowser insted of Firefox, as it does not allows you to
use the name Firefox or the Logo if you wan't to make changes to the
software)
Where GPL doesn't allow you to weaken the users freedom, the CDDL enforce
you to weaken the users freedom, thus they are incompatible.
