You are looking at a Particle Life Simulation. Change interactions between sets of particles by adding a rule.
If you just want to poke around, click on the presets tab. Otherwise...
Start by adding a rule. Enter the "Particle ID" for each particle to effect. First, type "0" into each box. Next, drag the slider in either direction. Click submit.
As you can see, the first set of particles are now either repelling (+g) or attracting (-g). Try different combinations of rules, to see the different patterns that can be created with just two sets of patterns.
Now, try adding more particles. Select a color by clicking the left box. Enter the number of particles you would like to add to the Petri dish.
Show me the code!!
Credits/cool stuff Clusters | Demo | Inspired code