I want to use a weak copyleft license for some new software project of mine. When reading the MPL v2.0 license text I stumbled over the following lines in section 10:

10.2. Effect of New Versions

You may distribute the Covered Software under the terms of the version of the License under which You originally received the Covered Software, or under the terms of any subsequent version published by the license steward.

Remembering the controversy when the FSF released GPL-v3 and some projects got converted to the new license without approval from all contributors due to being "GPL-v2 or later", I would like to avoid a similar scenario and restrict the license to "version 2.0 only".

How can I technically change the MPL-v2.0 license to exclude automatic version upgrades? Shall I put some notifier in all relevant source files (similar to the Exhibit B notifier), or just delete section 10.2 from the LICENSE.txt file in my project folder?

1 Answer 1


How can I technically change the MPL-v2.0 license to exclude automatic version upgrades?

You cannot change the MPL-v2.0 license to exclude the automatic upgrade clause.

If you remove clause 10.2 from the MPL license, then you have created a new license and you must call that new license by a different name. Only Mozilla itself is allowed to create new versions of the MPL license.

If not having an automatic upgrade clause in the license is important to you, then you should look for another license. The Eclipse Public License (EPL-2.0) might be a good candidate.

Creating your own license is the most secure way to ensure your project will see very little use, as every user will have to figure out how your license interacts with all the other licenses that might be in use in their project and that is work that lawyers get handsome paychecks for.

  • So I can only restrict the MPL-v2-covered code from being changed into strong copyleft by adding the notice in Exhibit B (as pointed out in sections 3.3 and 10.4), but not from being changed into MPL-v3.0?
    – blerontin
    Oct 15, 2020 at 14:40
  • Yes, that is correct. Oct 15, 2020 at 17:00

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