Foundation was developed for the needs of EOF so it makes sense there was a version for the Java WebObjects. There's almost certainly NeXT-derived code in macOS/iOS with a longer pedigree and a bunch of it will probably outlast the Foundation rewrite. As software evolution goes, it's an astonishingly long run, no doubt. Especially for a technology that very nearly went extinct.
Huh, Foundation was developed for EOF? (Enterprise Object Framework; it was actually very much like Rails ActiveRecord). I did not realize that, I always figured it came first.
There were already many Rails like frameworks when it came to be, I never understood the hype, specially since I was part of one written in TCL back in 1999, whose core team went on to create OutSystems in 2001.