Peteski: My experience with Unix is limited to a short time at work, when they sent us a PC running Xenix, which apparently was an off-brand Unix clone. Rather than write programs for a PC, or buy us a small mainframe, they wrote Unisys-mainframe-lookalike programs to run as subroutines, in a Xenix program, which we weren't supposed to see.
The problem was that, since it numbered each "program" we ran sequentially, and they only allowed 99 numbers, after a couple days the main program would refuse to start any more "programs". There was no elegant way to reset it, so they told us to power-cycle the machine. Of course, that killed all of the "programs" that were still running, which wasn't a good idea in a production environment.
Reading a novel, totally unrelated to work, I came across a throw-away mention of how to stop a program in Unix. Out of curiosity, I tried it, and it worked. Surprisingly, it also kept the print jobs that had already started running, so we could at least get control of the computer back.
We ran that mess for a year, before the other data centers got so fed up that Systems wrote all-new programs for Windows XP, and got us new PCs. The site manager and I both had programming experience, she'd worked as a production programmer, and nether of us ever told the company how we kept it running. Systems would probably not have liked "mere operators" messing with their software.