Difficulties maintaining a sufficient number of contributors to keep the project viable have persisted for several years. In January 2015, the project reported a lack of active developers and code contributions.[49] There have been continual problems providing timely fixes to security vulnerabilities since 2015.[50][51][52][53] In September 2016, OpenOffice's project management committee chair Dennis Hamilton began a discussion of possibly discontinuing the project, after the Apache board had put them on monthly reporting due to the project's ongoing problems handling security issues.[54][55][56]
Sounds like AOO is effectively dead, so this example is a fail to my challenge.
OpenSearch & ElasticSearch both seem alive, as well as OC & NC.
Neither https://github.com/privacyidea/privacyidea or https://github.com/eduMFA/eduMFA say either is a fork of the other.
I think you failed to share 3, 2 seem to valid examples of my challenge but the other 2 are questionable.
You didn’t ask for examples where both projects are alive!
NetBSD -> OpenBSD
To some extent I would argue that Linux is a spiritual fork of Minix and Unix.
But I think it’s also worth pointing out that these were in vastly different times where a single person or a small group of people could maintain an OS. An OS or browser is vastly more complex now.
BSD is a killer example of that point, too. Using a BSD Unix got to be pretty difficult after Linux containers became hegemonic.
If AMZN couldnt make their fire whatever it was called fork of Android really grow, what chance has the community got ?