Higher Order Voronoi Diagrams: A Java Applet

http://www.msi.umn.edu/~schaudt/voronoi/voronoi.html

Higher Order Voronoi Diagrams: A Java Applet
What is a Voronoi diagram? What is an order K Voronoi diagram? Let S be a set of n sites in the Euclidean plane. Informally, the Voronoi diagram is a subdivision of the plane into regions such that each point of a region has the same closest site. There are many variants, including the  order Voronoi diagram, which is a partition of the plane into regions such that points in each region have the same k closest sites.