I thought this would be more like MARS, but turns out to be bare-metal MARSCore War where I'm the scheduler. I'm not saying it a terrible experience, but I am grateful that my day job in IT is more higher-level.
Oups, I misremembered: the game is called Core War. In it, MARS ("Memory Array Redcode Simulator") is the name of a virtual machine that executes Redcode instructions. As a player, you write small programs ("warriors") to be loaded on the virtual machine where they try to prevail while klling off (overwriting) opponent programs.
This is lovely! An upgrades system would be really neat - like buying more cores, or bigger memory, or shooting users in the head when they don't log out after completing five tasks