A javascript implementation of the classis Growing Neural Gas (GNG) algorithm from the paper A growing neural gas network learns topologies.
You can click or drag on the input space to add input data. At each step one input data instance is randomly selected and is used to update the GNG. Use the sliders to adjust the parameter values, hover over a value to see a description.
If you are looking at this on bl.ocks.org/eweitnauer, make sure to click the Open in a new window link to see the parameter input elements.