https://en.wikipedia.org/wiki/IBM_i#Technology_Independent_M...
We probably still have a couple of PGM objects kicking around on our modern POWER hardware that were originally compiled on an old AS/400 system, but they run as native 64-bit POWER code like everything else on the machine.
The IBM midrange line gets a lot of undue disgust these days, it's not sexy by any means, sure, but just like anything running on modern day Z/OS you know that anything you write for it is going to continue to run decades down the line. Well, as long as you limit the amount of stuff you have running on 'modern' languages; because Java, Node, Python, Ruby, etc. are all going to need upgrades while anything written in 'native' languages (RPG, COBOL, C/C++, CL) compiles right down to MI and will keep working forever without changes.
The Machine Interface dates back to AS/400's predecessor, the System/38.
It's still updated by IBM and runs on POWER. It's just called "i" now.
I believe the naming went something like AS/400->iSeries->System i->System i5->i