Place Dictionary: The The Ruby on Rails application that handles the description of places with an underlying POSTGIS database.
GeoServer: The server that serves the geospatial data from the Place Dictionary directly from the POSTGIS database.
OpenLayers: The JavaScript library used to create the interactive map generated out of GeoServer.
GeoNetwork: The JAVA application we use to catalog spatially referenced resources (e.g. paper maps, online maps). It allows for mapping of its static maps on the Open Layers-driven Interactive Map.
Knowledge Maps: The Ruby on Rails application that handles ontologies, including the Place Dictionary's feature thesaurus, and the various ontologies drawn upon to describe places within the Place Dictionary.
The THL interactive map is made with OpenLayers and draws its GIS content from an instance of GeoServer. It also provides direct searching of the Place Dictionary, and browsing of the Knowledge Map-driven Feature Thesaurus, with results mapped directly on the map to the left.