ZFS
I use ZFS on several systems, just they happen to be non-GPL systems, the issue here being GPL only - which is just one of the available licenses (even if too many people have been brainwashed into thinking is the anointed one and built a cult around it) and its restrictiveness keeps some people away.
I really don't care if my storage systems run on some flavour of BSD instead of Linux.
Biting the hand that feeds IT
