Niels G. W. Serup, a Copenhagen-based programmer with a Master's in computer science from DIKU (University of Copenhagen), has spent three years building a cellular automaton framework called graffito. It is written in Futhark, a data-parallel functional programming language designed for GPU computation. The framework's entire purpose, as stated in Serup's FOSDEM 2026 talk title, is to produce "pretty cellular automata devoid of meaning." Conway's Game of Life simulates life. Wolfram's rules simulate computation. Each stencil in graffito — steal, coralreef, routefinder, collatz — simulates nothing. They are local rules that, when run in parallel on a GPU, produce global visual patterns that the author himself did not design.

There is a precise chisel-construct operation here. Cellular automata as a field has, over sixty years, developed a thick layer of construct: it is a scientific tool, meant to simulate reality. The Game of Life simulates birth and death. Langton's Ant models emergent behavior. Lattice gas methods model fluid dynamics. These are sediments of past chisel-construct cycles — what was once remainder got digested, named, and became disciplinary knowledge. What Serup does is chisel away the purpose of "simulating reality" from this construct. What is left after the chisel? Pure emergence itself — local rules producing global patterns that point to no real-world referent. That emergence is the remainder.

A deeper remainder lives in the tooling choice. Futhark is a compiler research project from DIKU — a purely functional language built for GPU parallel computation. Nobody uses Futhark for art; that is not what it was designed for. Serup uses it because Futhark's data-parallel semantics happen to align perfectly with stencil computation: each cell independently updates based on its neighbors, which is a natural map operation. But this "happening to align" is itself a remainder — the accidental affinity between compiler research and visual emergence, part of no one's plan. The stencil code itself continually generates surprise: routefinder was meant to visualize path-finding but "ended up being more about building mountains." The consistencyfier is labeled "Not sure yet." The framework invites anyone to submit new stencils — "I'll accept most things!" — meaning remainder production is open and ongoing.

graffito sits in a multiple naming gap: it is not generative art (no market, no exhibitions, no gallery presence), not scientific simulation (it explicitly refuses to model reality), not demoscene (no size constraints or competition targets), not a functional programming tutorial (though the code is remarkably elegant). It is a project that has been quietly growing on GitHub for three years, with talks at BornHack 2024 and FOSDEM 2026, belonging to the cracks between compiler research, GPU computing, creative coding, and visual emergence. No single field can fully name it. This is precisely what the beauty of the remainder looks like: the logic is still growing, the name has not arrived. Seeing it now matters more than seeing it later — because later, some field may digest it into construct.

Han Qin (秦汉) · @hqinjarsy · SAE Judgment & Aesthetics