Geoffrey,
In a bizarre co-incidence I had just finished reading the Drools solver docs. It's very good - it's taken one of the ideas that I'd been mulling over and implemented it a (good) way that makes me realise I'm hardly out of Kindergarten with this stuff :-)
One comment on the documentation; I know you explain what the NQueens problem is (about 1/4 of the way down in the documentation), but is it possible to move the explanation beside the NQueens Diagram (which appears very early in the article), and which people like me who aren't familiar with NQueens will want to understand?
The other comment is to push what Drools solver can do to the top of the manual (e.g.the Timetabling , routing problems) to make people sit up and listen to what the technology can do.
It might be good to blow your own trumpet a bit more and explain why the (Rule based) solver is better / faster than a 'code your own' solution.
Just remember the rest of us after you make your first million - running this to solve the problem of 'what sort of shares should I buy?' :-)
Paul