I am interested in learning about the current state of the art regarding forward chaining production systems. I understand that things haven't changed much (regarding the basic algorithms) since 1995's thesis by Robert Doorenbos, available here:
http://reports-archive.adm.cs.cmu.edu/anon/1995/CMU-CS-95-113.pdf
Am I right, or is there some other work I should be aware of?