> did they predate zones in Solaris?

Yes.

I wrote a history of this stuff in 2011:

https://www.theregister.com/Print/2011/07/18/brief_history_o...

FreeBSD jails first, then Solaris Zones, then Linux containers.

Linux VServer came first but is not really a normal container implementation, although it has similarities.

HP-UX 10.24 seems to be 1996:

http://www.bitsavers.org/pdf/hp/9000_hpux/HPUX_Versions.txt

I know next to nothing about it though.

> That doesn't refute my statement that BSD pioneered containers with jails

I'd say that was a fair call.

> I had thought IBM did VMs rather than OS-level virtualization

It does both.

AIX calls its containers WPARs:

https://www.ibm.com/docs/en/spectrum-lsf/10.1.0?topic=tips-o...

> (wasn't Gene Amdahl the one who came up with the rules for classically virtualizable architectures?)

No, Popek and Goldberg.

https://en.wikipedia.org/wiki/Popek_and_Goldberg_virtualizat...

FWIW I wrote a history of that, too:

https://www.theregister.com/Print/2011/07/14/brief_history_o...