Well, from public information: Meta has a huge social graph that helps support their social media businesses, and Google has a wealth of real world knowledge. These graphs are, I think, optimized for super fast 1 millisecond level query latencies, and not a rich query language (for example, not something like SPARQL).
I have just been looking at the Data Commons data sets, and I think I will add a fun example to my live Common Lisp eBook (and/or my Racket live eBook).
I have just been looking at the Data Commons data sets, and I think I will add a fun example to my live Common Lisp eBook (and/or my Racket live eBook).