I found direct links to several of the APIs and data files and they all have .uk extensions.
I was confused by the .com web site as well, not quite sure whether or not they are affiliated with the UK government..?
Probably not officially otherwise they would have a .gov.uk domain, but I imagine they must be at least loosely affiliated with the government to be pushing this sort of idea.
Yeah, that is a bit strange. I was expecting api.gov.uk or the like
Stranger still is the "usa" substring.... I had to read it twice to get the actual text :)
They have the .co.uk domain as well. Probably got both to help drive traffic.