The GeoNames Ontology makes it possible to add geospatial semantic information to the Word Wide Web. All over 11 million geonames toponyms now have a unique URL with a corresponding RDF web service. Other services describe the relation between toponyms.
The GeoNames geographical database is available for download free of charge under a creative commons attribution license. It contains over 25 million geographical names and consists of over 11 million unique features whereof 4.8 million populated places and 13 million alternate names. All features are categorized into one out of nine feature classes and further subcategorized into one out of 645 feature codes. (more statistics ...).
The data is accessible free of charge through a number of web services and a daily database export. GeoNames is already serving up to over 150 million web service requests per day.
GeoNames is integrating geographical data such as names of places in various languages, elevation, population, and others from various sources. All lat/long coordinates are in WGS84 (World Geodetic System 1984). Users may manually edit, correct, and add new names using a user-friendly wiki interface.
GeoNames has Ambassadors in many countries who assist with their help and expertise.