That means it gets spliced into the wiring for the crank/cam sensor, VVT, speed, MAF (or MAP system if you add one), and injector harnesses. The stock ECU gets inputs from the EManage that make it think the car is alright, while the EManage takes over running the injectors, spark, and VVT solenoid. I know that at least a few people in the early days (2006-2008ish) were using these and they worked to at least some degree, although they are definitely a hack compared to the more modern solutions.
That also means it's really generic - it'll splice into any car with injectors, coils, and a cam and crank angle sensor.
Because it's not specifically for the 2ZZ I don't know if anyone figured out how to get VVL to work with it, though - I think the stock ECU still runs the lift side when one of these was spliced in so the changeover point stays wherever it is in the stock ECU.