I realise that there is a certain latent distrust in assigning copyright to an entity, but let’s please call a duck a duck both on the forums as well as in the PR.
Here’s a handy overview of the relevant abbreviations:
CA = Contributor Agreement
CLA = Contributor Licence Agreement
CAA = Copyright Assignment Agreement
Where CA is a superset of CLA and CAA as well as some alternative methods like the DCO¹.
A CAA is an agreement where the contributor/author transfers/assigns his (full) copyright to the another person (or entity).
A CLA is an agreement where the contributors/authors grants another person (or entity) a license – i.e. some of his rights, but retains authorship (and other rights). CLAs can be very diverse, but roughly we distinguish between exclusive and non-exclusive CLAs:
- An exclusive CLA can be very similar to a CAA in that you grant (more or less limited) rights to just one person exclusively – i.e. grants an exclusive license.
- A non-exclusive CLA, on the other hand, is a licence agreement where you grant (more or less limited) rights to a person, but reserve the right to also grant them to others – i.e. grants a non-exclusive license (some well known ones are e.g. GPL, MIT, BSD, Apache, MPL).
To make it more concrete: What ownCloud has in place is a CAA (with an implicit exclusive CLA fall-back for jurisdictions where full-on transfer of copyright is not possible) – authors assign/transfer their rights to ownCloud, Inc.
What Nextcloud has in place (or seemingly plans to through the C4) is so called Inbound ≡ Outbound licensing, which simply means that the community agrees that it will only accept contributions under the very same (inbound) license as the project’s (outbound) license. This by definition is a CLA.
So, please, let’s avoid confusion and properly call ownCloud’s agreement a CAA and Nextcloud’s situation an (as of yet not entirely documented) non-exclusive Inbound ≡ Outbound CLA.
1: Developers’ Certificate of Origin is arguably also just a CLA. I am amongs those that argue so as well.