Anemone components are still working great, extending the abilities of Grasshopper. Here, Tuğrul Yazar studied a space-filling fractal called Gosper-Peano curve. Be very careful about the number of iterations (the N input) because it can crash your Rhino if you change it to bigger numbers.
Also you should have Anemone components installed in order to run this definition. The generator curve is a special one. Direction, length and angle of every segment make it possible to create this beautiful fractal.