For now see OwnCloud
page which contain information on both ownCloud and Nextcloud. Nextcloud forked from OwnCloud and is still compatible. Mageia 5 repos have ownCloud server packages, and a Nextcloud 10 package. Mageia 6 and up have Nextcloud server.
The plan is to create this page about only Nextcloud before Mageia 7 release, as a clone from OwnCloud a bit simplified and updated.