I am somewhat intrigued by the diagram found here representing 1800 years of cultural history in an imaginary world some guy created. This sort of thing would seem to have strong applications for game development, insofar as world design. It looks like he did this diagram by hand. What I'm interested in is seeing if there is a way to create this sort of diagram programatically. If you were tasked with generating diagrams in the style of the above from random values, how would you go about it? Are there any particular data structures or algorithms that you would consider?