CRAZY DUMB ZEALOT
I'm curious: does compiled Linuxdoom run successfully if you manage to strip it of all the graphics, sounds and player input overhead, remaining a mere console utility instead? Keep in mind that the game logic must still work fully, but nothing to display other than relevant text messages at the DOS prompt (no video mode change, no waiting, no music, no sound).
All this is in the interest to have access to the whole Doom logic (WAD support, gameplay thinking, monsters, things...) so I can take advantage of it if I want to code a demo-recording bot, without actually having to see it record in real time. Imagine having the ability to autorecord (with varying success) a megawad within a single minute or less, because there's no rendering overhead.
Or turn Doom into a text-based adventure where player input commands have the effect of pausing the game, unpausing, moving him forward, to the left, shooting etc. And you get text messages describing what you see, what happens, what will happen (thanks to the predictable random numbers, resulting something like "sergeant is going to shoot you without having time to go to cover if you don't shoot him now") and so on.
I actually tried to remove all the rendering code, but I wasn't sure what exactly to delete (I was fearing that gameplay logic might be hidden in R_ files too, for example), and wasn't sure if it would work at all, so I opted for an Eternity fork instead, benefiting both from full vanilla support and high-end mods this way -- but scrapping the idea of a non-drawn Doom code then.