Supported by a grant from the John S. and James L. Knight Foundation in 2015, the New York Public Library and its partners developed gamified tools to add geographic context to NYPL collections.
One "game" allows users to add a specific location to the places depicted in historical NYC photographs in the NYPL’s Digital Collections. Once these photographs are geocoded they can be searched on a map base at OldNYC. You can contribute to this effort of geocoding photographs of NYC by “playing” Surveyor.
Another crowdsourced mapping “game” is Building Inspector, where among other tasks, you can help by transcribing historical information like addresses from old fire insurance maps of NYC. In addition, you can align historical maps with today’s map through a process called georectification (or georeferencing) with the Map Warper. All of these projects are opportunities for you to contribute your skills and knowledge to enhance the NYPL's map image database for all researchers.