M/PC – A Concatenative OS

A tiny new project called M/PC has shown up promising a very unusual way to use a computer: no file browser, one command line at the top of the screen, and a style where you build actions by stacking words together. In plain English, it’s a minimalist system for managing files and launching programs in a stripped-down virtual machine called Varvara. You can move around with controller buttons, save command sequences into files, and even load a wallpaper on boot. Very neat, very retro, very likely to make half the internet clap and the other half squint.

And yes, the squinting started immediately. The biggest fight in the comments was the classic “is this really an operating system, or just a fancy shell?” debate. One commenter basically kicked open the door with that exact question, while another admitted, in the most relatable way possible, that they "don’t really get how this is different to just piping between commands." Translation for normal people: some readers think this is a bold rethinking of how computers could work, while others think it sounds suspiciously like old command-line tricks with extra steps.

The vibe got even spicier when people noticed strong similarities to Forth, an old stack-based programming style, with names like dup, over, and rot waving giant nostalgia flags. Then came the jokes: one person warned everyone not to confuse M/PC with the old MPC computer standard, and another dropped the most delightfully nerdy name theory of the thread: is it just "CP/M" reversed? In other words, the project launched as a niche experiment and instantly became a comment-section identity crisis, complete with retro in-jokes and “what are we even looking at?” energy.