The macOS CIFS client was from BSD, not from Samba.

slownews45 · on June 30, 2021

BSD's have also taken a pretty strong stance against GPLv3 - again for violating their principles on freedom.

I can't dig it up right now but someone can probably find it.

But the BSD's used samba for a while as well.

easton · on June 30, 2021

As of Darwin 8.0.1 (so Tiger?) smbclient(1)'s man page was saying it was a component of Samba. I think some BSDs used Samba.