Prove you're human by playing Doom in a captcha

"Can it run Doom?" is a clever way of reminding us that everything, from toasters to tealights, are general-purpose computers underneath the polypropylene. Though Doom in the browser is nothing new, Doom in a captcha in a browser as a test of humanity is a potentially disarming development. But you'll be needing those arms to kill three baddies—the measure of mankind as far as the captcha is concerned. Guillermo Rauch writes up how he did it.

A CAPTCHA that lets you play DOOM® to prove you're human (for educational and entertainment purposes.) The project works by leveraging Emscripten to compile a minimal port of Doom to WebAssembly and enable intercommunication between the C-based game runloop (g_game.c) and the JavaScript-based CAPTCHA UI. Some extensions were made to the game to introduce relevant events needed for its usage in the context of a CAPTCHA.

Whatever next? Build a functioning redstone CPU in Minecraft in a captcha?

Previously:
How to power your calculator with potatoes so you can play DOOM
Playing DOOM via Twitter
This guy built a set-up so his rat could play Doom
I put some Doom in your Doom so you can Doom while you Doom
Doom running in task manager with each CPU core as a pixel, supposedly
How to play DOOM on your fleshlight