I will fully agree on OS/400, of the operating systems and platforms I have worked with, it is by far the most stable. That is easier to achieve when your op

I will fully agree on OS/400, of the operating systems and platforms I have worked with, it is by far the most stable. That is easier to achieve when your operating system only runs on your own proprietary hardware. (No mess of millions of drivers to write for one). It worked well for years without any sysadmin touching it. Well my mom was trained to be the "sys admin", which meant rotating backup tapes.