It is a (very good) software protocol that enables DAW’s to be used with Avid control surfaces. e.g. Avid S3, Avid Artist Series etc. Way better than Mackie MCU I would argue.
Ok, it is somewhat of a niche area, probably hence why it is being neglected by Steinberg but come one… us Eucon users still deserve a bit of love after years being left out in the cold.