Adopting a permissive license



There has been a lengthy and very productive discussion here at CERN/IT about our strategy in terms of software licensing of our Open Source products. We would like to update the community on this and launch a public debate on the matter.

TL;DR further below.

Indico, like many other pieces of software produced at CERN over the years, has adopted the GNU Public License from the beginning. The decision of adopting that particular license was done at a time when Open Source Software was the exception rather than the norm and the majority of FLOSS projects were using it.
In my opinion, GPL was never a perfect fit for Indico, not because of its core principles, but rather because it has been conceived in a world where web applications didn’t exist. GPL-licensed web applications are in a kind of grey area which only lawyers can navigate: they have no binaries, no linked libraries and thus the spirit of the license cannot be correctly applied. The FSF later came up with Affero GPL, which clarifies things, but unfortunately in a direction that I believe won’t benefit Indico as a project.

The biggest problem with Indico and (A)GPL comes not for us (developers) but for those who are developing their own extensions and plugins for the platform - they would normally be required to provide their users with the source code of their own module, since it uses Indico’s core, which would be itself (A)GPL. While it’s not our intention to ask our legal service to prosecute anyone who doesn’t wish to share their Indico plugin, this state of uncertainty is not good for anyone and we’d rather eliminate any ambiguities. We would also like to incentivize the adoption of Indico outside of the research sector, which is already happening and which we believe could benefit from a more permissive license. We are committed to keeping Indico free and contributing our work back to society, in accordance with CERN’s mission. In our view, doing so in a less restrictive way will foster its adoption and contribute to the development of other sectors of our societies.

In the last 10 or so years, much has changed and GPL itself has become the exception rather than the norm. I won’t go into this matter in detail, because there is no shortage of resources describing the two licensing modules and their pros and cons. But it’s clear that many large projects (as well as almost all libraries we rely on) have made the choice of a simpler and more permissive license. This adds to our belief that we are making the right choice. Among the options that are currently widespread, we chose the MIT license, for its simplicity and since it is very similar to CERN’s original WWW license.

The timing is perfect for a license change, since we’ve just rewritten Indico basically from scratch. We therefore aim to release Indico 2.2 as MIT.

So, summarizing:

  • We’d like to change Indico’s license from GPLv3 to MIT;
  • The main goal is to clarify the legal status of plugins that are developed but not shared with the community;
  • We believe this will be good for the Indico ecosystem and society as a whole;
  • We intend to release 2.2 as MIT-licensed software;

This is especially important to those (non-CERN developers) who have contributed to Indico since the 2.0 rewrite. We will of course need your express permission to change license.

We’re looking forward to knowing your opinions/feelings.

UPDATE: GitHub issue -


Yes, using a more permissive license seems fine to me.