These sorts of charts always fall short because they never explain how they were influenced. If you're not in the know already, this provides little information to you. Prolog influenced Clojure, but how? If I didn't already know about core.logic, I'd be scratching my head about why. And even then, it took me a good minute to rack my brain to think of some possible way they were connected because it's not obvious.
I dunno, I found it useful in that my favourite language (Lua) has some interesting connections I wasn't aware of before, such as the influence on Io, which is new to me.
Point is, it was sort of fun to browse around and see just how incestuous our language universe is...
This graph is based on influence relation data from the now defunct Freebase, which combined various data sources including Wikipedia. Gephi was used for the graph layout, node sizing and coloring and Sigma.js is used for rendering in the browser.
FYI: "The data on programming languages, their influence relations and the programming paradigms they are classified into comes from the Freebase Programming Language collection, which is largely based on information from Wikipedia. Freebase data is not necessarily correct or complete."
Is the colour scheme also determined by the network? Why are there only two light blue bubbles, on opposite sides of the map? I guess this could also use a better algorithm for embedding.