To name a few, heavy plows, padded horse collars, fresh water carp farming, water mill improvements, and ships changed in design. Ships became larger but adapted in shape and rigging to e operated by fewer sailors. I think the stern post rudder came to Europe around this time (not sure of the date range though).
Lynn White's classic study, "Medieval technology and social change", looks at three broad innovations: the stirrup, which led to mounted knights as shock troops and the feudal reorganization of society to support them; the agricultural revolution driven by iron horse-drawn plows and three-field rotation; and the development and exploration of medical mechanical power and devices.
The most important was the horse collar, which was like turbocharging a tractor. The use of horses to farm also exemplified the class changes. Horses didnt die of plague. Thier owners sure did. So the horse became cheaper and lesser classes of people put them to uses that previously would have been benieth thier dignity.
