The Digital Aeronautical Flight Information File (or DAFIF) is a set of files that contain data on airports, navaids, waypoints, special use airspace and other facts relevant to flying in the entire world. This data is provided by the US military, through the National Geospatial Intelligence Agency (NGA), and is primarily developed for the benefit of military aeronautical operations, but was made available to the general public.
Except for the United States, which is also covered by data provided by the FAA, it is usually the ONLY comprehensive digital data available for pilots. Other countries either don't provide digital data at all, or they do it through a proprietary web interface or in non-reusable formats (like PDF files of scans of paper documents). Even within the US, there is data that is available in the DAFIF which is not in the FAA data. For instance, the navaid.com database generators use the DAFIF data to find ICAO identifiers for airports in Alaska, Hawaii, Puerto Rico and other places where there 3 letter FAA id is not enough data to generate the ICAO id.
Attention! This source will be removed at october 2006 of the public access for several reasons. Look here for more details and support the existence of DAFIF. You can also help creating a replacement solution here.