@zverik @simon MapQuest supported Nominatim for several years too, although I think Lovia was doing a lot of work.

Don't neglect the role of the community in innovating though: Wille created OSMCha to deal with some particular problems with edits in Brazil (openstreetmap.org/user/wille/d). HOT Task Manager has antecedents in QualityStreetMap (wiki.openstreetmap.org/wiki/Qu) & OSM Matrix (wiki.openstreetmap.org/wiki/Ol. MapCraft also a nice tool in this space.