Here's the link to the project page. http://vis.cs.ucdavis.edu/~ogawa/research/storylines/ It says there that this visualization is based on a XKCD comic (about lord of the rings).

The guy is the same that the code_swarm visualization: http://vis.cs.ucdavis.edu/~ogawa/codeswarm/ If you didnt see it before, go there and watch the impressive videos about eclipse, apache, python and postgres.

The guy is using processing.