NYC Open Data : Clearinghouse for data from all New York City agencies. Much of this data in this collection is already in GIS friendly formats.
BYTES of the Big Apple : Portal for the geographic datasets provided by the NYC Planning Department. Includes tax lots (Mappluto), various boundaries and facilities, and official street centerline (LION) files.
- LION - Direct download of street centerline files with street and borough code address geolocators included
CoreData.nyc : Map based data hub for housing and neighborhood resources from NYU Furman Center for Real Estate and Urban Policy.
NYPL Map Division
- NYPL Map Warper : A tool for online map georectifing. You can also browse and download maps that have already been georeferenced (export options include GeoTIFF, PNG and KML formats as well as WMS and tile server links).
- Digital Gallery : Digital collections include a wide-array of scanned maps.
GeoData@Columbia : A wide variety of NYC specific datasets and maps can be found in our own collections.