The pgm module implements a shell hook so that when an unknown command is typed, we look into the mounted filesystem and look for a file with the same name as the command. If we find one, we load it in memory and run it.
When I zasm-ified the shell a couple of dozens of commits ago, I inverted push and pops...
Let go of that "meta os" thing. it's not as meta as I made it sound like. It's a kernel.