tl;dr We moved all the Doctrine PHP projects from LGPL to MIT license successfully in roughly 4 weeks. For that we used a small web-based tool to ask the permission of 358 authors that contributed in the last 6 years.
The Doctrine project has been LGPL licensed since it was started in 2006. When I first started contributing in the project late in 2009 we were constantly asked about changing the license to a permissive license such as MIT or New-BSD. My subjective feeling is that there are much more libraries with permissive licenses than 10 years ago. And there are others that back my feeling up with facts. The fear of getting screwed when using a permissive license has probably declined in favor of the benefits. As Lukas puts it:
Maybe with enough experience you start to realize that it happens close to never that a proprietary fork of an open source project ends up outpacing the original project.
We wanted all the benefits of permissive licenses as well. So at the beginning of this year we as Doctrine project first started to investigate how the task of switching the license could be done. After a short email with the FSF it was clear that we had to get the approval of every single committer or remove their code.
VLC successfully attempted a license change last year from GPL to LGPL, so we we're hopeful to get this done. After discussing with Lukas we came up with the idea of a tool that helps this process, so I wrote it. It features:
- Import of all commits from one or many Github projects
- Aggregation of commits to authors based on e-mail address from Git log
- Status approved/not-approved for every author.
- An e-mail engine to send a request for approval to every author using the awesome Mailgun service, who has not approved yet. We use Mailgun for fun and to have a way to act on bounces easily.
- Admin functionality to mark commits as "trivial or deleted".
- An audit trail to account for all changes and who has done them.
- Symfony2/Doctrine2 application with debian packaging using FPM.
This project is not yet open-sourced but will be when I have some time to clean up the hardcoded passwords and write a small README on how to adjust the templates.
After importing the commits of all the LGPL licensed Doctrine projects we realized that we have 358 unique committers and about 40-50 without an e-mail address (from the old SVN days). So we started googling for nicknames and eventually collected all e-mail addresses except maybe 6-8 missing ones.
Now after 4 weeks of bi-weekly e-mail reminders, everyone except 16 committers have accepted the license change. No single person refused the change. All commits of the 16 people left we're luckily not part of the code base anymore when we completely rewrote Doctrine 2 or trivial one-line changes.
I am very happy to announce that Doctrine is now an MIT licensed project. Have fun with it.