The whole OS is essentially a really big nosql database, the filesystems are journaled and you have “files” but you also have dynamic files called “print queues” and executables are “jobs” that run queries and output into queues.
I know at least two of the major hotel chains use them still in their core network.
I’ve worked with this monstrosity, it’s not unlike other mainframe operating systems like IMB’s “System i”
I believe there’s still developers out there working on modern versions of it
https://www.rocketsoftware.com/sites/default/files/2025-09/universe-feature-release-matrix.pdf
The whole OS is essentially a really big nosql database, the filesystems are journaled and you have “files” but you also have dynamic files called “print queues” and executables are “jobs” that run queries and output into queues.
I know at least two of the major hotel chains use them still in their core network.