As @tmdugan points out, we put an ArdenService and began developing a LogicService to process logic rules. The logic service got complicated and usage fell to the point that it was only being used by the CHICA team. Logic was pulled out into a module, was used almost solely by CHICA with an older version of OpenMRS (maybe 1.6?), and I don’t believe ever got ported to subsequent versions of OpenMRS. The ArdenService actually still exists in openmrs-core, but hasn’t gotten any attention or use since circa 1.6 (>5 years ago?). This will eventually get removed from core, but (obviously) hasn’t been a priority for the community.
If there’s interest in using Arden with OpenMRS, I would suggest migrating the ArdenService into a module and evolving it into a proper Arden Module that could be used by other modules that want to compile & run MLMs.
It might have been @tmdugan, but I believe @vanand was working with her and did the bulk of the coding for the ArdenService. Not sure is she’s still hanging around (Vibha, that is). 