Marc
1. GeoNames is not using a Named Entity Recognition library.
2. GeoNames is using a mix between NLP, statistics and heuristics
3. No ontology technology is used
4. GeoNames. What else. It is the largest freely available Gazetteer.
There is a chapter on the GeoNames RSStoGeoRSS converter in the "The
Geospatial Web" covering some details of the implementation :
http://www.geospatialweb.com/
http://www.amazon.com/Geospatial-Web-Geobrowsers-Information-Processing/dp/1846288266/
Cheers
Marc