Thanks for that. I see now that it's linked from the article—I'd previously overlooked it as the article seemed to imply it was the product of their volunteer programme, but it seems it isn't:
> The building information was developed with sensors from low altitude aerial imagery.
> The building footprint and height information was captured and developed in 2013.
There's also Atlas[0], not mentioned in the article, which seems to be a (open-source/non-free??[1]) tool released by Apple for use specifically with OSM data. Really interesting stuff.
I got the link from my notes of the StateOfTheMap conference where an Apple representative was speaking. They have full-time staff now, claim 1 month training. It sounded like a dozen people.
