minifb VS deno-canvas

I would also recommend looking into SDL2 or MiniFB for cross-platform support, as not everyone uses X11.

MiniFB is what you want for this.

MiniFB maybe?

But you can have a skeleton program that sets up framebuffer for you (e.g. with minifb or TIGR), then link it that skeleton with your code (in assembly or whatever you prefer).

I also saw minifb, which seems like a really to-the-point way to get a buffer I can draw to., so I guess I will go in that direction (rust lib, make FFI bindings for deno, etc.)

If you just want to push pixel data to a frame buffer then I can highly recommend minifb. MIT licensed, Supports a lot of platforms, and it’s about as simple as you can get. It also handles input if you need it, too.

I think this library will fit your goals: https://github.com/emoon/minifb

sdl2 gets around the first problem by downloading a CLI service & starting it, that speaks JSON over a TCP socket. It's a limited surface of the API, and missing some pretty basic stuff, but I could see it working ok. It's not canvas, so I'd have to translate those sort of calls to it. I discussed that a bit here and it sounds like I could blit images of the canvas to sdl2 surface, but since it doesn't support in-memory images, I'd have to implement that in sdl2, or save a "frame" image to a file, for every blit. Either way, I have the overhead of redrawing every frame as a complete image. This seems incredibly jenky, and I assume will not perform very well, but I haven't tested.