Interactive standalone simulations of the core algorithms from Mitchel Resnick’s Turtles, Termites, and Traffic Jams: Explorations in Massively Parallel Microworlds (1994).

Each simulation demonstrates how complex emergent behavior arises from simple agent rules in decentralized systems — no central controller, no global plan.

Simulations

Artifact	Algorithm	Emergent Behavior
traffic	Nagel-Schreckenberg traffic model	Spontaneous jams propagate backward
boids	Reynolds flocking (separation/alignment/cohesion)	Coordinated flock movement without a leader
termites	Termite wood gathering	Scattered chips self-organize into piles
fire	Forest fire percolation	Critical density threshold for fire spread
ants	Ant foraging with pheromone trails	Efficient paths emerge from random exploration
slime	Slime mold chemotaxis	Cells aggregate into clusters via pheromone gradients
predator-prey	Wolf-sheep-grass dynamics	Lotka-Volterra population oscillations

Architecture

Each simulation has a strict two-layer split:

• sim/*.js — Pure algorithm modules. No DOM, no Canvas, no Math.random(). Deterministic when given a seeded PRNG (mulberry32 via sim/rng.js). Exports createState(), step(), and domain-specific helpers.

• *.html — Self-contained interactive artifacts. Import from sim/ via ES modules. Own the Canvas rendering, UI controls, and animation loop.

Changelogs

Each HTML artifact includes an inline changelog section visible at the bottom of the page. These record post-release bug fixes with enough detail to understand the problem, diagnosis, and resolution – no commit log or issue tracker required. See predator-prey.html and termites.html for examples.

Running

Open any .html file in a browser. Each artifact includes:

• Play/Pause/Step controls
• Parameter sliders for real-time tuning
• Live statistics display