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by belorn 4018 days ago
License incompatibility happens when two licenses has different conditions which both need to be happen in order stay in compliance.

Its very easy for a license to fix this. They can either use common conditions, or they do like GPLv3 and have a list of additional conditions which may be added in order to be compatible with other licenses. MPL do not have that, nor does CDDL, and thus we have the situation where they are incompatible with most other copyleft licenses.
2 comments
bahamat 4017 days ago
I don't see why it's on the CDDL to fix. CDDL is a file based source license, the resulting binaries can be freely linked against binaries with different licenses. Section 3.6 explicitly says so!

The primary difference between MPL 1.1 and CDDL 1.0 with MPL 2.0 is that sections 1.7 and 3.3 of MPLv2 explicitly bow to GPL, a concession made by Mozilla to attempt to end this nonsense. Section 3.7 of MPL 1.0 and 1.1 (3.6 of CDDL) are clauses that imply GPL compatibility, without explicitly naming GPL. That wasn't good enough for the FSF, thus, MPLv2.

MPL was chosen as a template for CDDL because sections 3.7 (CDDL 3.6) gives it a quality like BSD, that the binaries can be larger works with different license terms while the rest of the license retains the copyleft qualities of the source code. Thus, CDDL would have "all the advantages of BSD, all the advantages of GPL".

Any supposed incompatibility is in the legal opinion of the FSF, who never stated their reasons, only the final conclusion, preventing healthy discussion on the matter.

Since the FSF and GNU identify all versions of MPL and CDDL to be "free" and "copyleft", why is the burden on CDDL or MPL? The FSF could have solved this by explicitly naming MPL/CDDL in GPLv3 (as they did with AGPL).

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the_why_of_y 4017 days ago
The MPLv2 was specifically designed to be compatible with as many FOSS licenses as possible. It was not possible to make it compatible with GPLv2 however, because the GPLv2 is incompatible with any license that has explicit patent clauses (which I would consider to be a historic accident and a serious issue with GPLv2).

That issue was resolved with a specific section in the MPLv2 that allows licensing the code under (L)GPLv2+/AGPLv3+.

  1.12. “Secondary License”

    means either the GNU General Public License, Version 2.0, the GNU Lesser General Public License, Version 2.1, the GNU Affero General Public License, Version 3.0, or any later versions of those licenses.
The MPLv1.0/v1.1 allows automatically upgrading to any later version of the MPL, in section "6.2. Effect of New Versions. ". Therefore (IANAL etc.) any code published under MPL is compatible with GPLv2+.
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