Kamikaze is being used in both the LinkedIn social graph engine as
well as the search engine.
Release 1.0.8 has been in production for over a year. We did release
2.0.0 not too long ago, but that was only porting Lucene api changes.
3.0.0 is with some real new stuff, we are planning on putting into
production as soon as possible. It is being worked on by Hao Yan, one
of the the guys from the lab originally developed this technique.
-John