ANN RabbitMQ is migrating to Mozilla Public License 2.0

[Michael Klishin]

Dear RabbitMQ community,

On behalf of the core team at VMware, I have an important announcement to make.

As you know, RabbitMQ server and core plugins are currently licensed under the Mozilla Public License 1.1.

Over the years we have lobbied Pivotal and then VMware legal to allow us to change this as

most projects who have used MPL1.1 originally have moved on to another license, such as MPL 2.0 [1][2].

This has led to repeated questions about MPL 1.1, whether it can be used in commercial projects,

how "viral" it is, is it compatible with license X or license Y, is it a "license trusted in the industry" and so on.

Recently we have been cleared to proceed to an "upgrade" to the MPL 2.0 license. This can be done

by our team without involving every contributor to the project. We intend to start the migration some time

in the next month (June-July 2020). We expect that a RabbitMQ version after 3.8.5 will likely be the first

release to be distributed under the MPL 2.0.

As far as RabbitMQ users are concerned, there are next to no changes (if you were able to use OSS RabbitMQ

before, you very likely will be allowed to under the MPL 2.0) but you are encouraged to read

the FAQ of both licenses [2][3] as well as an MPL 2.0 Revision FAQ [4], and run this by your legal

team if applicable.

The migration will benefit RabbitMQ in several ways:

• We won't be using a license that is considered to be "obsolete" and "obscure" by some current and prospective users.
• In general, the core team will have to answer fewer licensing-related questions and spend more time developing RabbitMQ.
  
• MPL2 explicitly mentions GPL, BSD and ASL2 compatibility (see Q13 and Q14 in [2]), while with MPL 1.1 we had to double- or triple-license our client libraries to eliminate potential compatibility confusion.
  
• MPL2 is arguably easier to reason about than 1.1.
  

Some may ask why haven't we adopted ASL2, a very popular license. There are many reasons for that but

ultimately the biggest hurdle by far is that it would be a drastically more involved process for our team.

MPL 1.1 to MPL 2.0 migration is going to be straightforward and does not require involving every contributor

(going back to 2006). MPL 1.1 to BSD or ASL2 would likely involve

a lot more legal review time, with no guarantee of success.

So this migration is a pragmatic choice: we take

the option we can use today, address most of the concerns listed at the top, and clarify GPL, BSD and ASL2

compatibility for those who need it.

If you have questions about the migration, please ask them in this thread.

Thank you.

1. https://www.mozilla.org/en-US/MPL/2.0/
   
2. https://www.mozilla.org/en-US/MPL/2.0/FAQ/
   

MPL 2.0 FAQ — Mozilla Mozilla's experience with MPL 1.1, and the experience of some of our advisors, was that in practice license incompatibility is often resolved by the use of custom additional permissions or dual- and tri- licenses. Each combination of dual or tri-license, or custom additional permissions, further complicates license interaction and proliferation ... www.mozilla.org



3. https://www.mozilla.org/en-US/MPL/1.1/FAQ/
   

MPL 1.1 FAQ- HISTORICAL USE ONLY — Mozilla MPL 1.1 FAQ- HISTORICAL USE ONLY. Français (une version plus tôt). This is an outdated FAQ, and is retained only for historical purposes. The FAQ for MPL 2.0 is here.. This is the Mozilla MPL FAQ. www.mozilla.org



4. https://www.mozilla.org/en-US/MPL/2.0/Revision-FAQ/
   

About MPL 2.0: Revision Process and Changes FAQ — Mozilla About MPL 2.0: Revision Process and Changes FAQ 1. How was MPL 2.0 drafted? MPL 2.0 was drafted over a period of 21 months in a public process that included extensive feedback from a variety of people, including MPL users, lawyers, and open source community groups like the Free Software Foundation and Open Source Initiative. 2. Is the revision ... www.mozilla.org

[Joachim Haugberg]

 Hi, 

Great News, any update on an  release date for version with 'upgraded' license to MPL 2.0. I guess version 3.8.6 is a candidate? 

BR. 

Joachim Haugberg