Credit: The airport database was first put together by Patrick Baudis, and then extended by Guenther Eichhorn.
The airport data for USA airports are updated regularly. Data for other airports are updated only very irregularly.
IMPORTANT: None of the data can be used for flight, they are for non-critical personal information only. The actual data may not be accurate, not be up-to-date, or they may be faulty to begin with. Do not rely on these data in any way. The FAA is the primary authority as to the "real" information for all information regarding USA airports.
Several search pages are available:
Search for Airport Records on aerobaticsweb.org