The breakdown as I understand is as follows:

- Owncloud: The 'original' platform, written in php, still developed today

- Nextcloud: A fork of Owncloud (php) by some of the people that worked on it, including the project founder over directional differences, now more widely used than the original Owncloud

- Owncloud infinite scale (OCIS): An implementation of the Owncloud server in Go, with the goal of making it faster and more scalable than the PHP version

- Opencloud: A fork of Owncloud infinite scale (Go) after an acquisition of ownCloud, the company.

My biggest problem with Nextcloud is that it intentionally broke (at least twice by memory) on some updates, wanting me to run some oci command on the box. Remember that "for my family" also means "for my family when I'm gone." I never got round to having to find an alternative thanks to the divorce, but I'd consider Nextcloud a complete non-starter for this reason.

Find an alternative.

I don’t know about owncloud, but I have been hosting a family Nextcloud instance for a little under two years and it works fine.

It’s boring. It works.

Nextcloud is written in PHP, which doesn't sound scalable to me.

OwnCloud is written in Go but employs an open-core model. Some features are locked behind a proprietary paywall.

The good OwnCloud is abandoned, and instead they released some meme enterprise nonsense.

I'm running NextCloud, but I hesitate to call it good, because of its kitchen sink approach to features. I really want 2015 era OwnCloud with just files, it being PHP/MariaDB/Apache-based. I refuse to use anything that requires Docker, which is most of the slop alternatives currently available.