This mod is a proof of concept, OK? Please don't use it in anything serious. It might break at random, or do wacky uncharacteristic things at any given point. Got it? Okay, on with the show.
KubeJS: RTJC is a plugin for KubeJS that allows you to compile and run Java code at runtime. The speed is probably abysmal, it's not very simple to use, but god damn it I had fun making it, so you have to endure it.