Actually I wrote the first version of this graph library 3yrs ago. It was to help the search relevance team create reusable components, turn implicit dependency management into a first class citizen and finally add a way to dump the graph state at runtime or statically.
Looks like just one, from the list of major contributors.
But, Google really has no right to whine about this. They make an explicit tradeoff: they manage to stay 3-5 years ahead of the curve of everyone else by not open sourcing their impressive libraries and infrastructure. But the corollary of that is that there's no place to whine "we got there first!" when someone else produces an implementation of X.
