A new javascript/canvas-based tool is added to the Fun stuff page by my 12 years old son and me, that lets one small dot grow by moving blocks in random direction, coming from the edge of the screen. If a moving block comes next to a block that are already placed on the grid, it will stuck there and a new will appear at the edge of the grid. Such kind of fractal image generation is called “simulation of diffusion-limited aggregation” and the generated images are called “Brownian tree clusters“.
Watch this in action here.