Just a heads up, but Games Workshop went after the vassal guys pretty hard when people started uploading 40k army stats. I would be very careful with anything GW related just FYI.
Not sure how it would go today (they're giving away licenses to anybody with a pulse and an iOS app on their resume right now), but back in the day they were very protective of their IP.
Hey thank you! I tried to open a vmod file but it crashed my terminal.. we're looking to make the rule-set human readable as well as machine readable with the above repo.
It has an amazing number of "modules": games implemented on it.
It is written in Java.