Well, to answer that question, let me make an analogy. There's no required set of features for calculators either. Technically a tiny box that can only add two

Well, to answer that question, let me make an analogy. There's no required set of features for calculators either. Technically a tiny box that can only add two numbers can be considered a calculator, since it calculates. I guess we might call it so, but it isn't the same, is it? It's just that people tend to think about povray and renderman when "raytracers" are mentioned, and thus, fitting a raytracer into 30 lines of javascript may seem impossible, while actually it's entirely possible because the core idea of the algorithm is quite simple - this is what this demo shows and it is exactly the reason it's a good demo.