The CDDL release announcement[0] says: """ Thus, it is likely that files released under the CDDL will not be able to be combined with files released under the G

The CDDL release announcement[0] says: """ Thus, it is likely that files released under the CDDL will not be able to be combined with files released under the GPL to create a larger program. """ So the creators of the CDDL didn't think they were compatible. What do you mean when you say "have come to the conclusion that they're unlikely to be incompatible"? Do you believe one could combine the Linux kernel and ZFS into a single source tree and distribute binaries under the terms of the GPLv2? [0] https://lwn.net/Articles/114840/ https://lwn.net/Articles/114840/