OpenStreetMap by Ciro Santilli 34 Updated +Created
It is rare to find a project with such a ridiculously high importance over funding ratio.
E.g., as of 2020, their help login help.openstreetmap.org/ shows MyOpenID as an option, which was discontinued in 2014, and not Google OAuth.
They do still seem to have a bit more activity than gis.stackexchange.com/questions/tagged/openstreetmap on Stack Exchange.
Complaints:
All of this is a shame, because they do have some incredible data that you cannot find easily on other maps because people just edited it up.