I look at a project under MPL 1.1. Can I take the source and re-distribute it under MPL 2.0 without any modification or contribution? That is, I am not a contributor (not the initial, not in the past, not in the future).

Some other licenses (Apache) seem to state clearly the unmodified parts (in this context: all parts) retain their original license. For MPL 1.1 -> 2.0 (or any other license), I miss such a statement. Is there a difference between a version upgrade (1.1 -> 2.0) and a license change (MPL 1.1 -> Apache).


2 Answers 2


In principle, different versions of license X are different licenses. This means that a "version upgrade" of a license should in principle be treated as a license change.

However, some licenses explicitly contain provisions for version upgrades. In that case, a version upgrade of the license can be applied at any time by anyone who legally obtained a copy of the code.
The MPL license contains such an version upgrade clause, but the Apache license does not.


If a project is licensed under the MPL-1.1-or-later (which it implicitly is, unless otherwise stated), you can redistribute it under the MPL-2.0. For this, replace the LICENSE file and the licence headers.

If a project explicitly states that the licence is MPL-1.1-only, you are still allowed to do this. For this, apart from updating the headers, add the following notice:

This Source Code Form is “Incompatible With Secondary Licenses”, as defined by the Mozilla Public License, v. 2.0.


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