TrueNAS
A network storage operating system built around ZFS, developed by iXsystems. It was called FreeNAS from 2005 and was renamed in 2020 when the free edition and the enterprise product were brought under one name.
The point is getting ZFS's advantages — checksums on all data, self-healing on read errors, snapshots that cost almost nothing and replication to another machine — without configuring them by hand. On top sits sharing over SMB, NFS and iSCSI, user management and a web interface. For years there were two branches: CORE on FreeBSD and SCALE on Debian, where SCALE added container-based apps and became the branch development consolidated around. It wants plenty of RAM and, ideally, disks attached directly with no RAID controller in between — ZFS wants to see the physical drives itself.