You can now run Doom in Doom on PC

pcgamesn.com:

It’s been a long time coming, but finally we arrive at the singularity, the natural end to our journey to discover everything and anything that can run Doom. As T.S. Eliot wrote, “the end of all our exploring will be to arrive where we started, and know the place for the first time.” Like all pilgrimages, this has always been a voyage into the self – and now here we are, the very end, the Doomception.

Yes, you can now run Doom inside Doom. YouTuber and coder Kgsws – whose online handle even sounds like a Doom console command – explains how they were searching for a way of launching their own executables within Doom itself, and naturally came across the “SpawnMapThing” command, normally used to place weapons, enemies, and powerups into Doom’s levels.

A certain portion of the “state” code, which dictates what state an item or enemy is in (for example, it may be at frame number one of its death animation, or frame number five of flashing on the spot to get a players’ attention) can be replaced with an executable – like for example the DOS version of Doom. There are a few bug fixes which Kgsws, seemingly a magician of sorts, swiftly works out, but otherwise, it seems almost simple. And bang, you copy and paste the executable code over the state code, and Doom is running in Doom.

But Kgsws doesn’t stop there. What begins as a tiny room, simply displaying a run through of Doom, quickly evolves into a fully fledged cinema-cum-gallery, where you can dim the lights, hit switches to disable HUD and mouse-look, and instantly jump in and out from playing your own Doom, to the on-screen Doom within Doom.

It’s beautifully done, but also bittersweet, as it seems like there’s nowhere else to go now when it comes to getting Doom to run