> in the 90s with "Beowulf" clusters

In case of any confusion, that sort of thing wasn't a generic Beowulf feature, but it sounds like Bproc. I don't know if it's still used. (The Sourceforge version is ancient.)

https://updates.penguincomputing.com/clusterware/6/docs/clus... https://sourceforge.net/projects/bproc/

Containers actually only make it harder to "orchestrate" your distributed processes in an HPC system.