In 2006, Ars Technica published an April Fool's article[0] declaring that the perennially-forthcoming Duke Nukem Forever would finally see the light of day... as... a browser game! Ho ho, how droll.
Use 3D CSS to enhance a 2D page with some flair. But be aware, 3D CSS, it's trying to solve things that most realtime 3D rendering does not, like intersecting planes need to be subdivided in order to correctly handle transparency. This means 3D CSS has an O(N^2) or worse type of issue vs rendering yourself using WebGL or WebGPU where you'd avoid those issues. This demo probably does not intersect any planes but the browser itself has to check for those intersections anyway. TL;DR: If you're going to make a 3D web game use WebGL or WebGPU, not 3D CSS
Works smoothly in Firefox. But the default key mapping is busted: fire at Alt means that it opens and closes the menu in Firefox with each press. Also, Alt + left arrow ends the game and goes back in history.
Interestingly, it was more choppy in Chromium.
I could not find a key for moving sideways ("strafing").
Creating 3D scenes with CSS has always been possible[0], but like this project, it's required JavaScript for interactivity.
But there's a lot more CSS features now. While in the past, Turing completeness in CSS required humans to click on checkboxes, now CSS can emulate an entire CPU without JavaScript or requiring user interaction.[1] So I wonder if DOOM could be purely CSS too, in real time.
> Yes, Lyra Rebane build a x86 CPU completely in CSS, but that technique is simply not fast enough for handing the game loop. So the result is something that uses a lot of JavaScript.
In recent years CSS has become closer to a full programming language through experimental features, for example in 2025 they added if statements and some math functions like modulo
I was amazed when I first came across CSS scroll snapping. It's great for creating immersive experiences where one part of the page fills the entire screen while native browser scrolling still works.
I ran calypso.z3, tristam_island.z3 and a few more Zmachine text adventures under an interpreter created in PostScript.
Also if I want I can cross-compile a static build of Frotz for Linux/Misc and emulate it under a RISC interpreter for Linux syscalls written in... Perl, runable in every modern Perl port out there. Linux/RISC binary under Perl for NetBSD/Vax? Yes. Slow? Not much, it's a text game in the end.
But, as for the ZMachine, you can run text adventures in Android,
Game Boy, Amiga, MSDOS, Windows, Palm PDA's... anything 8bit and up.
Also, damn Sokoban under Eforth written in Subleq, a VM which can just:
- set up a 2^16 RAM size
- single opcode: substract A from B, if less than 0, go to addr in C.
- A < 0? Get ASCII input in B
- B < 0? Put ASCII output in B
- C < 0? End
This, just this, and people wrote Subleq simulators in C, AWK, Python, TCL, FPGA's and whatnot. And it will run Eforth, and that means... you can write a
ZMachine interpreter on it and be really slow if emulated in a Pentium 4 (maybe 3/5 seconds per command with a ZMachine on top of Eforth for Muxleq instead of Subleq), but the game will be playable and a great exercise on Turing completeness.
If a Mandlebrot render under Muxleq+EForth (with no floats used, just integers) is as fast as a C64/Amiga with a native Forth. then having that tiny EForth+Muxleq is not that useless.
Is CSS that awesome? It's still a language designed for styling webpages with 30 year of added features. I'd argue something purpose built would be a much better tool for the potential usecases people try to use CSS for now.
I guess I am asking, if modern CSS is so awesome, it's awesome compared to what exactly?
I think the argument lies in its flexibility and versatility (regardless of it being the most efficient or effective tool for this one particular task).
Duct tape is awesome for the same reason -- even though there are several effective use cases for duct tape where a different tool would technically be "better" for the job.
I am not sure what a purpose-built tool would look like, but the CSS-like language you see in UI frameworks like GTK is tailored for styling actual UI's.
In CSS on the web, just centering a div has historically been a problem. We have flexbox now, but what if CSS was designed with our current needs from the get-go?
Crazy to see how far we've come.
[0]: https://arstechnica.com/gaming/2006/04/forever/
Use 3D CSS to enhance a 2D page with some flair. But be aware, 3D CSS, it's trying to solve things that most realtime 3D rendering does not, like intersecting planes need to be subdivided in order to correctly handle transparency. This means 3D CSS has an O(N^2) or worse type of issue vs rendering yourself using WebGL or WebGPU where you'd avoid those issues. This demo probably does not intersect any planes but the browser itself has to check for those intersections anyway. TL;DR: If you're going to make a 3D web game use WebGL or WebGPU, not 3D CSS
Very cool demo though!
EDIT: https://cssdoom.wtf/
Interestingly, it was more choppy in Chromium.
I could not find a key for moving sideways ("strafing").
All in all, quite mind-boggling.
But there's a lot more CSS features now. While in the past, Turing completeness in CSS required humans to click on checkboxes, now CSS can emulate an entire CPU without JavaScript or requiring user interaction.[1] So I wonder if DOOM could be purely CSS too, in real time.
[0]: https://keithclark.co.uk/labs/css-fps/ [1]: https://lyra.horse/x86css/
> Yes, Lyra Rebane build a x86 CPU completely in CSS, but that technique is simply not fast enough for handing the game loop. So the result is something that uses a lot of JavaScript.
https://www.simplethread.com/new-and-upcoming-css-features-i...
The post here could really use it though. The main content is pushed to the bottom of the page!
Also if I want I can cross-compile a static build of Frotz for Linux/Misc and emulate it under a RISC interpreter for Linux syscalls written in... Perl, runable in every modern Perl port out there. Linux/RISC binary under Perl for NetBSD/Vax? Yes. Slow? Not much, it's a text game in the end.
But, as for the ZMachine, you can run text adventures in Android, Game Boy, Amiga, MSDOS, Windows, Palm PDA's... anything 8bit and up.
Also, damn Sokoban under Eforth written in Subleq, a VM which can just:
- set up a 2^16 RAM size
- single opcode: substract A from B, if less than 0, go to addr in C. - A < 0? Get ASCII input in B - B < 0? Put ASCII output in B - C < 0? End
This, just this, and people wrote Subleq simulators in C, AWK, Python, TCL, FPGA's and whatnot. And it will run Eforth, and that means... you can write a ZMachine interpreter on it and be really slow if emulated in a Pentium 4 (maybe 3/5 seconds per command with a ZMachine on top of Eforth for Muxleq instead of Subleq), but the game will be playable and a great exercise on Turing completeness.
If a Mandlebrot render under Muxleq+EForth (with no floats used, just integers) is as fast as a C64/Amiga with a native Forth. then having that tiny EForth+Muxleq is not that useless.
https://github.com/howerj/muxleq
No
>No
Yes
Use Deutex, GNU make and Pillow for Python to compile.
Then wou will have up-to-date IWADS to be used aywhere. No need to put ID copyrights, just a mention to FreeDoom creators.
Also: a modern CPU is around 10000x faster than the 486 CPU Doom was designed for. Per core.
I guess I am asking, if modern CSS is so awesome, it's awesome compared to what exactly?
Duct tape is awesome for the same reason -- even though there are several effective use cases for duct tape where a different tool would technically be "better" for the job.
You can keep it high level but your comment makes me think you have something in mind, and I'm honestly curious.
In CSS on the web, just centering a div has historically been a problem. We have flexbox now, but what if CSS was designed with our current needs from the get-go?