Today's top news in Sweden is a revelation of how the police keeps a register or computer file on certain categories of people. Anyway, a side track of this discussion is that they apparently are using a software called Analyst's Notebook, which is useful for tracing connections between individuals. This software is made by i2, now owned by IBM.
http://en.wikipedia.org/wiki/Analyst%27s_Notebook
I think this kind of software could be useful in tracing relationships between historic writers, artists, inventors, and politicians. Who socialized with, learned from, or inspired whom? Even though Wikipedia contains lots of basic facts, the large patterns of connections are not so easily visible.
Are there any examples of counterterrorism software being used to better understand history? Are there any free/open source and/or web based versions of such software?
All that I have seen of DBpedia is much more primitive than this.