The data source is the papercliff API, the scripts that make the analysis are written in Clojure, the visualization makes use of the vis.js library, and the data are open. All these are available at https://github.com/papercliff
Also, there is the r/papercliff community, with more content.
tommytornado t1_j6sijdo wrote
Where is the data from? Which territories, languages? What do the colours signify? What is a 'keyword' - most mentioned?